Induced demand as a concept just doesn’t make sense. If demand is “induced” it just means that the supply wasn’t adequate to meet demand. That’s it. It isn’t a large mystery, and there isn’t any logical argument or evidence that greater supply will keep “inducing” demand infinitely. There are a finite number of people and finite minutes in a day, and if they are able to derive value from driving more, then they will do so, but only up to a limit. In return for that driving, they will also gain something for it (the value that motivated them to drive). The phrase “induced demand” is simply a part of the rhetorical war waged by anti car activists.
I’m also not sure why we need to create a false dichotomy between roads and bike lanes. I need driving to shuttle between home, work, schools, and other activities in a time efficient way. I also like biking for exercise and leisure, although bike commuting hasn’t been practical for me when I’ve tried it. Have cities considered elevated bike lane networks on pillars built into highway medians or sidewalks, so we don’t have to choose just one or the other? What about cantilevered elevated walk/bikeways? Or perhaps they can have an underground driving network like Chicago does.
It's also about altering development patterns (suburbanizating) that spreads stuff out more and forcing everyone to drive more or even buy a car in the first place even if they'd prefer a walkable town.
I'd like to see a study across all road construction whether excessive induced demand is a guaranteed effect. In all articles related to it I only see examples cherry-picked where induced demand negated the effects of adding lanes. However, it's not clear whether this is universally true, true enough to be a rule of thumb, or something that only occurs in specific situations.
Anecdotally, removing toll plazas in favor of plate scanners and adding bridge lanes to the Goethals Bridge in Staten Island, as well as widening the Staten Island Expressway, has significantly reduced traffic delays and improved safety for several years. There _are_ more vehicles using the road but not enough more to significantly negate the improvements.
How fast does demand grow? Does it ever stop or slow down? I know for a fact that far from every highway and road in America is congested: the majority are not. Even many if not most roads in metropolitan areas are not. So you can’t extrapolate demand increases ad infinitum for the current moment.
I don't know the data (or this area particularly well generally), but intuitively I would expect induced demand to be seen in the majority of cases of roads being updated for increased capacity.
Not because of a necessity that any capacity increase must always cause it, but because the decisions of which roads to expand are made by humans who, with the exception of edge cases (maybe the reason for rebuilding was because of the state of the road and increased capacity was a secondary affect rather than the main motivation; maybe corruption led to a poor choice being made; maybe forward looking expecting future demand to increase years later based on other factors like planned new buildings) wouldn't spend money increase capacity unless road traffic has been increasing and looks like it is't about to start trending in the opposite direction soon enough to make expanding the road a pointless short-sighted exercise.
Aka if increasing road capacity wouldn't induce more demand, how likely is it to be in a situation where it's considered worthwhile expanding it?
If you expand a road, there will be greater usage because demand soaks up supply.
However, cars are big and takes up a lot of space, especially since people regularly drive sedans that seat only one individual with max capacity for four to five people. This requires a lot of space to support cars.
Of course, you can continue to expand roads. Problem with that idea is that the roads displace other uses of land such as homes and businesses.
Roads increase utility of cars, for sure, but that comes at the expense of everything else.
Don't forget bankrupting municipalities and states by misallocating untold sums of money toward road construction and maintenance and not investment in human capital: schools, healthcare, and other high-ROI public goods.
It’s easy for people to forget just how spatially inefficient cars are because we’re so used to 30-40% of city space being dedicated to roads and storage.
We saw a dramatic example of this next to the bike path I ride to daycare/work: hundreds of new apartments, restaurants & other retail shops, outdoor public spaces, etc. next to a subway station. This was just part of a retail parking lot which broke 50% usage _maybe_ a couple of times a year. The number of people using the space when up by at least an order of magnitude and it’s a lot more consistent economic activity.
> If you expand a road, there will be greater usage because demand soaks up supply.
This can only occur when there is sufficient latent demand, or phrased differently, the supply of roads (and sufficiently fungible transit modes) is so insufficient that that moderate increases in supply do not create a surplus. This lack of surplus (traffic) representing an economic inefficiency which it can only be desirable to reduce[0].
What is stupifying is how 'induced demand' (read: building more roads will cause more people to perform economic activities facilitated by transit) is contorted into an argument against building roads.
[0]Until such point that traffic inefficiency is in equilibrium with others. e.g. I can't see Manhattan widening 5th ave anytime soon, but most of America isn't pressed for real estate.
The article points out that more supply of roads also leads to less density, which requires more driving, which requires more roads. This is not the short-term induced latency but for sure a part of it and part of why katy highway exists.
Lets look at the null position and agree that induced demand is bad and we shouldn't build more roads, which means the question becomes:
How many roads should we be tearing up[0], and how do we know when we've torn up the correct amount? Since we a. clearly aren't at the optimal amount of roads[1], and b. induced demand argues that we shouldn't be building more.
I don't find it nonsensical at all. My city is actively planning to reduce the amount of normal roads in the city center and introducing more & better bicycle lanes. This is very much needed, since while the central crossing does have (some) gutter bike lanes leading to it, it comes close to suicide to use them. Accordingly, no one does and many use the sidewalks that are already too small for comfort without bikes (the city is in a bad spot there, because it's very space constrained in that place. The roads are badly overloaded in the center and no lanes can be added due to the lack of space).
A nearby larger city would be well advised to remove traffic & lanes from central locations and allow more bike paths and crucially allow expanding the badly overloaded subways with trams (and dedicated tram ways) near the center. Due to various factors, there's no real option to use more tunnels.
They have been routinely over the limits for particulate matter and were successfully sued over it.
Now, roads outside of cities are complicated. The larger ones usually can't be easily reduced, but eat a lot of maintenance costs that could go towards higher capacity options (rail). Looking at https://en.wikipedia.org/wiki/Braess%27s_paradox and carefully analyzing existing roads may also make sense. In general, car based travel costs society the most per mile by far. Introducing measures like tolls & car-free cities as well as making alternatives more attractive with shifted spending may reduce demand and thus enable tearing down roads.
The question hinges on a false dichotomy that the only solution to demand is more roads, which is part of what this article is arguing against.
Edit: An obvious but politically hard solution to overloaded roads is encouraging higher density.
> If you expand a road, there will be greater usage because demand soaks up supply.
Only up to a limit, as I mentioned. They won’t keep “soaking up” supply. People are not looking to drive 24/7. They are looking to reach destinations and spend time there.
> Of course, you can continue to expand roads. Problem with that idea is that the roads displace other uses of land such as homes and businesses.
This seems like a vague argument. Road space displaces other uses marginally. If your population were held equal, then you can build more roads, displace some amount of other uses, and the increased traffic from those displaced wouldn’t be nearly as much as the extra traffic capacity the road provides. If your population increases or usage patterns change, then it is simply “latent” demand that is being met, since there’s an appetite for more travel throughout and increased speeds and all the utility that brings. All of this applies to anything that we can model with supply and demand, including bike lanes.
Based on your tone, it seems like you are critical of the article, but your critique is actually what the article is addressing. Specifically, "Effect 2" demonstrates a unique property of "induced demand" that doesn't fit into traditional discussions of supply and demand.
> I’m also not sure why we need to create a false dichotomy between roads and bike lanes.
Because there is finite width for existing roads between existing buildings, and so quite literally, adding a bike lane often requires removing a car lane. It's not a false dichotomy at all, it's literally measured in meters.
> Have cities considered elevated bike lane networks on pillars...
Do you have any idea how astronomically expensive that kind of stuff would be? It's just not even on the table, realistically speaking, for 99.9% of places.
We have some of that in my city, alongside a big freeway (see [1]) and yes, it’s ridiculously expensive. It is great though, and one of the only options given the number of very busy intersections this popular route crosses. But in the inner city, it wouldn’t make any sense.
Inside the CBD, they’ve been taking out on-street parking to put in separated bike lanes, and that‘s just as good. They completely removed car traffic from a bridge in the middle of the city also to add an extra bus land and a bike lane, and while some drivers were annoyed, it used to drop you in a extremely congested bit of the city so wasn’t very convenient in the car anyway.
The article ought to do more to distinguish these.
Latent demand: Driving more often because we can now actually get to places when we used to give up trying.
Induced demand: Driving more miles per day because space for the roads pushed each building farther apart over time. Going to larger stores because small nearby stores failed to compete.
I have yet to receive a convincing answer why induced demand does not similarly apply to/or is not a concern for welfare programs, homeless shelters or public transportation. I find it suspect that this theory is apparently only applied to roads, and largely by people who commute by bike.
I said convincing answer. My read is that by the theory of induced demand the best way to eliminate bike deaths is to eliminate bike lanes and therefore people on bikes.
The best way to eliminate car deaths is to eliminate cars, too. But obviously we're not doing that either.
I'm not clear what you're trying to accomplish by juxtaposing induced demand with transportation fatalities, when the two concepts don't seem to have any special connection.
I'm sorry, who are "induced demand folks"? What does that even mean?
And I'm unaware of anyone proposing the elimination of cars as serious policy. At most it's limiting vehicles in parts of dense pedestrian city centers.
People who are generally "left-leaning" on transportation envision a healthy mix between public transportation, cycling, and cars. They simply want car usage to be balanced with alternatives, rather than cars dominating by default.
Virtually everyone recognizes that cars are necessary for a wide variety of uses. They're not going away, so I don't think you need to worry about that.
> why induced demand does not similarly apply to/or is not a concern for welfare programs
It does in certain circumstances, like when you'd get 90% of your paycheck if you quit your job, and so people quit. Which is why smart welfare programs provide benefits in a gradual way rather than at a single cutoff -- e.g. how the Affordable Care Act subsidies were designed.
> homeless shelters
Again, it does. Cities with excellent homeless shelters and care literally attract homeless people from parts of the country without. Remember the scandal about cities literally buying homeless people bus tickets to send them somewhere else, to try to address the problem? This is a known issue, and a good justification for why social services funding ought to be provided at the national level rather than at the city level.
> or public transportation
It does absolutely. Entire cities spring up after a rail line is built.
I guess my question to you is -- what are you trying to argue? Induced demand isn't just a property of roads, and I don't know any author who says it's exclusive to roads. It seems like a straw-man you've constructed.
But the concept is often raised in conversations about roads, because many people naively believe that widening a road will solve congestion.
It gets applied to roads because people keep trying to “solve” traffic without pricing roads. Nobody likes being stuck in traffic, but unfortunately it seems most people are also angrily opposed to tolls which would balance supply and demand and allow roads to flow smoothly (for those willing to pay). There’s a faction of people who _swear_ that if we just built one more highway we’ll _solve_ traffic. That’s who the “induced demand” argument is aimed at.
To your broader point, all services work like this to a point; if you first suppose there’s insufficient supply to meet demand, then adding supply can induce more demand. There’s an eventual saturation point for everything though. Tear down all the buildings downtown and replace them with parking lots. There will be plenty of unused parking and no more rush hour as there’s no longer a reason to go downtown.
> Induced demand as a concept just doesn’t make sense. If demand is “induced” it just means that the supply wasn’t adequate to meet demand. That’s it. It isn’t a large mystery, and there isn’t any logical argument or evidence that greater supply will keep “inducing” demand infinitely. There are a finite number of people and finite minutes in a day, and if they are able to derive value from driving more, then they will do so, but only up to a limit. In return for that driving, they will also gain something for it (the value that motivated them to drive). The phrase “induced demand” is simply a part of the rhetorical war waged by anti car activists.
Right, it's not surprising but highway expansions are often sold as "reducing congestion" rather than the reality of "causing more people to drive more miles with the same resulting level of congestion."
If the actual goal of highway expansions is to make it efficient for people to drive more miles/have longer commutes then there isn't an issue with there being "induced demand," but there may be various reasons why this isn't actually a very good goal.
Highway expansions do have benefits to people who end up moving further out (more affordable housing), but there may be better ways to achieve the goals of providing housing to more people around urban areas by increasing density, or to help people get around urban areas by transit, etc.
> There are a finite number of people and finite minutes in a day, and if they are able to derive value from driving more, then they will do so, but only up to a limit.
This is the primary objection I have to self-driving cars. By enabling people to do other things while they are travelling, self-driving cars raise that limit considerably. When self-driving takes off, so will congestion.
This is very true. Hopefully the Boring company can be successful in reducing tunneling costs by a factor of 10 or 100. Then cities will just have to fined the political will to allow them to be built. Maybe public, self-driving taxies can be made to travel close enough together so that they look like and can be called "trains". Then all the public transport supporters might not try and block them even if the tunnels are open to people's individually owned vehicles also.
> Induced demand as a concept just doesn’t make sense. If demand is “induced” it just means that the supply wasn’t adequate to meet demand
Supply and demand aren't fixed -- they meet at an equilibrium price. There are latent trips that are canceled, change modes, or time-shifted to deal with traffic because of the high cost.
> The phrase “induced demand” is simply a part of the rhetorical war waged by anti car activists.
Induced demand is a standard transportation engineering concept. You might argue that it's been hijacked by the anti-car folks or whatever, but tramsportation engineers and planners who want to build car-heavy transportation systems are aware of and use it. They taught it to me in a very conservative civil engineering department.
No, but it can make them visible and willing to be treated. If people cant afford private health care or are unwilling to travel long distances or wait for a long time on a public health waiting list, they might just put up with being untreated. This is quite common for things like joint replacement or chronic dental issues.
If you're only thinking about the already-there population, no. But many hospitals have patients that travel to get there.
Building a Mayo Clinic hospital in Arizona results in more sick people traveling there for care than otherwise would have.
Seems like there are some natural ways this could cause a loop. Now we hire more doctors and train more new specialists. That burnishes the reputation even more. Now more people want to come!
(One thing to note is that it's generally always a localized increase, not an absolute one. The people living in the new suburbs that you built a new shiny road to still would've lived SOMEWHERE in the country. You didn't increase that country's total demand for transit. You just redirected it into "road transit from this particular suburb" from wherever it would've gone in the absence of building that suburb.)
The part I always miss, is how is this a bad thing when it comes to roads? Building 'hospitals'[0] for people to use until there are enough hospitals[0] that people no longer have incentive to flock to the new Mayo Clinic in Arizona seems pretty desirable.
Thats because roads are not "supply" it is "price". Building a hospital and staffing it should make the cost of healthcare in an area lower because there is more "supply" of healthcare. Which in turn means more people would go get healthcare that couldnt afford it before. The sick people are already there, they just cant afford to get treatment.
Just like the people who want to drive somewhere are already there, but the cost of a clogged commute makes it not worth it for them to spend the time, so they do something else.
I think that what will spur the use of bike lines is the surge in electric two-wheeled vehicles: e-bikes and e-scooters and such. Thanks, I suspect, to improved battery tech, those things are everywhere.
Bike lanes will not induce much demand if all you have is human-powered cycles. Maybe on sunny days, in flat areas.
I would love to be able to bike to work. But I can't, even if there were bike lanes. I live in an American suburb, which by design is located far from industrial areas, where jobs are. Too far to bike. There are a few high-density residential buildings in the CBD, but they are only affordable for millionaires. The public transportation here is for show.
Two years ago, the highway nearby completed a 5-year widening project. During that time, traffic was so bad I had to check Google Maps every day to find out which route I should use. Now that the project is complete, I never check Google Maps anymore. I just use the highway without even bothering, as the cost to drive on it is now clearly the cheapest. My life is better in the short term, but eventually more homes will be built, traffic will increase, at some point I'll have to go back to checking Google Maps every day, and they'll start another road-widening project.
I've lived here long enough to experience this cycle first-hand, and nothing has changed logically that would stop this loop from executing again and again. At some point, I'm sure a physical limit will be reached. Either we run out of space, or run out of money, or something else.
Electric bikes really change the "too far to bike" equation. Depending on your fitness level and the route, you could easily ride 10 miles (or more) and arrive with minimal sweat.
I agree about the "too far to bike". my current commute is 30+ miles. It still falls into the "too far" category. I do plan on moving within 10 mi which I'm very interested in the bike. Issues still stand that it limits my ability to run errands during the day. I don't run errands every day, but now I'd have to plan. Another downside is I live in Phoenix where summers are 110degF for 60-70 days. Winter is nice!
I'm within 10 miles, so now I guess I need to go to some city council meetings and lobby for a bike lane or sidewalk or something. Right now, of all the highways leading to this industrial park (yes it's well within city limits), none of them have a sidewalk or bike lane. The road shoulders are high grass. It's not a new highway either. This highway has been here literally for decades. Yet it has no sidewalks, bike lanes, or shoulders. Plenty of room to build them. The will is simply not there.
Good idea. 10 miles is a very bikable distance (my ride is 8), but it sounds like the bigger problem is your roads are only built for one kind of traffic.
There are some crazy cool electric mopeds and motorcycles now too (6k watts+). Small, <100 lbs, 50 mph, 30 miles+ range, full suspension, nearly silent... so fun. Seems like they fly under the radar enough to not attract attention but are still ridden around on the roads unplated or in the bike lanes. Personally I don't care but some people get mad at that stuff. I'm of the opinion that its one less car on the road. Maybe some infrastructure will be dedicated to those types of vehicles because riding on the roads is just too dangerous considering that the flow of traffic in California is often 60+ mph on regular sized throughways.
Anecdotally, I'm seeing a lot more kids and teens on e-everything
These are "electric mopeds and motorcycles", legal street vehicles that are operated on streets, not bike lanes or sidewalks. They fit in the same niche as 49cc scooters and 125cc motorcycles, and are quieter and cleaner.
I agree which is why I would like to see more infrastructure dedicated to these types of vehicles. They don't quite fit into bike lanes as long as there are actual bikers (also bike lanes in the US generally suck). Riding on sidewalks sucks for pedestrians. Riding on roads is too dangerous in my opinion because drivers suck and traffic moves too quickly. So, higher power e-vehicles are stuck to roads and bike lanes because there's nowhere else to ride.
I've heard they are difficult or impossible to get plated (seems like it depends on whos working at the dmv). A lot don't bother because emopeds are stealth (small, look like bike, quiet), so people/police don't bother them unless they're being a total dick
There are two other reasons bike lanes don't have the kind of demand induction properties that roads do:
-Bike lanes (and ultimately, bike destinations) have way higher humans-per-square-foot of road / parking lot density than cars lanes. The throttling mechanism on behavior for the car example is ultimately drive time, and new lanes quickly become capacity constrained (first at the interchanges; later at the parking; last in the lanes themselves) in a way that slows ultimate travel back to the indifference equilibrium. The equivalent for bikes tolerates a way higher flow of humans.
-Induced demand for cars is in part a function of the fact that you can (up to a point) drive at any speed, meaning that if roads are added that support commuting in from 30, 40, 60 miles away, that can be a doable commute. There is no amount of development that will create a 60 mile bicycle commute. Here, the demand induction mechanism with travel lanes and housing is reversed: you need convenient housing to drive the demand for bike lanes.
The reason bike lanes do not have demand induction effects is because there is inherently low demand. A majority of the population cannot use bicycles for long trips, and even those who can cannot use them for all trips.
Bike lanes are ableist and classist. Only healthy citizens with an excess of time and energy are able to use them for trips. The elderly, children, those with heart conditions, asthma, or many other health conditions, and anyone needing to transport anything heavier than their own body cannot use the lane. In most cities this represents a minority of the population. Creating exclusionary space for bicycles is the opposite of progressive policy and efficient urban design.
What a weird take. Bike lanes do not take away the possibility for those less able to use a car, they strictly add options. You might as well argue sidewalks are ableist.
> Bike lanes do not take away the possibility for those less able to use a car, they strictly add options.
But, that is true only if the bike lanes are “free to build and maintain”. Otherwise, the city is allocating money toward bike lanes rather than something OP would argue is “less ableist”.
Since bike lanes suffer way less stress due to less weight (to the power of 4!), they are a lot cheaper to build and maintain for the same throughput. But they do take some money, for sure.
(I know basically zero about city planning, although I have lived in cities for a decade)
The “roadway” itself is another fixed resource, I think? So, either the street gets a bike lane or another vehicle lane, but not both because there is only so much space between the two rows of buildings.
Yeah, that gets into the whole "take the space away from cars" thing.
My opinion is that in cities due to the much higher throughput of bike lanes it can also help reduce congestion, but if the bike lanes don't get used, e.g. due to a fractured network with "high-risk" shared road in-between or very unattractive gutter lanes, that doesn't really do anything. My hope is that cities would be aware of that and that it would only be a temporary thing, but the whole point that initiatives of Strong Towns and others like Not Just Bikes make (among others) is that many cities don't seem to have a clue on how to handle transportation, especially mixed-mode.
I am specifically considering removing traffic lanes on e.g. a bridge or a main thoroughfare in favor of bikes. This is common in New York where I live.
One particularly egregious example is removing a lane of traffic on the Brooklyn Bridge in favor of bikes. This is in my opinion an oppressive action in favor of the wealthy who live in downtown Manhattan and downtown Brooklyn.
The wealthy (and wasteful) are the people driving into Manhattan every day. Making the Brooklyn Bridge a viable bicycle route (the shared lane is constantly packed with tourists) will open a key route for people who can't afford cars to commute.
Have you seen how crowded the Manhattan bridge bike path gets, especially at rush hour? I don't deign to assume anyone's socioeconomic background, but it's also very clearly a wide swathe of the NYC population (I somehow doubt the folks on delivery bikes are living in the wealthy areas).
The bridge serves a large swath of NYC (south Brooklyn, Staten island, the Rockaways) and Long Island. Dumbo and downtown manhattan are upscale areas.
Were the city willing to invest in the project in a sane way, such as making a separate bike path like the one on the Manhattan Bridge or another tier, obviously it would add value. But as it is as a lane removal it's a lazy and badly planned move that snarls the middle class in traffic (which is already regularly backed-up onto the collapsing BQE) to allow the upper class to "enjoy" a "scenic" ride next to a bunch of smog blasting trucks. And maybe help a couple of door dash drivers I guess.
If the healthy and able population overwhelmingly traveled via bike, alternate forms of transit would gain too because currently they are being CRUSHED by the amount of road traffic in many cities. Busses that move at a crawl. At-grade trains limited by traffic intersections. Taxis and ambulances fighting traffic. Etc.
If you look at other countries with a lot of bike infrastructure, you can see that your point doesn't really hold up to reality. First, reducing road usage so only those who can't use a bike (for whatever reason) helps everyone, since it allows more efficient transportation and encourages a denser city (see the linked post). (this partially handles time, in dense city centers bikes can be often faster already)
Most people can use an electric bike (this checks the energy part) and with electrical cargo bikes can transport a lot without a lot of physical exertion.
And, last but not least, for those who truly can't use anything bike-like the fan-favorite netherlands allows the use Canta, very small microcars, on bike lanes. These are way cheaper than cars and need less skills to drive, so elderly can drive them as well.
Way better than requiring everyone to drive couple tons worth tens of thousands of dollars after absolving an expensive and time consuming course on how to use them without injuring anybody or worse.
PS.
I don't know many children that can drive a lot on roads without a bicycle. That's a very weird example. I don't think many people advocate removing sidewalks in favor of bike lanes.
It’s unfair to consider electric bikes as most bike lanes are explicitly not designed for them. They operate at a higher speed than regular pedal bikes and are more dangerous to pedestrians and cyclists. We may as well suggest that everyone use electric motorbikes and then car lanes will carry much more traffic.
Also, obviously children are not driving cars. But they still use the road as passengers. It is much less common and mostly not possible to have children too large for a baby seat but too young to travel on their own (4-12 years old or so) using a high traffic bike lane.
> They operate at a higher speed than regular pedal bikes
They can, but don’t have to. Strange would be the market were bicycles only capable of going at 20mph or 0mph were used.
> We may as well suggest that everyone use electric motorbikes and then car lanes will carry much more traffic.
Good idea!
> It is much less common and mostly not possible to have children too large for a baby seat but too young to travel on their own (4-12 years old or so) using a high traffic bike lane.
Most parents are not physically capable of operating such a contraption regularly. I would hate my life if I needed to lug my kids in that contraption when I want to take them to the park, doctor, grocery store, or any life activities. In a bike lane with e-bikes and racing bikes overtaking me constantly
Hmm, maybe it would help if I added an electric motor. But my kids are still at risk of injury if I’m hit by irresponsible cyclist, it will be a horrible tangle of metal and limbs. So maybe we should be in some kind of enclosure…
And when everyone adds enclosures i.e. ends up in a car, you’re at much more risk than you were before and have all the harms of car-centric urban planning.
The physical ability of people is historically specific and if people were to generally cycle most would be able to ‘operat[e] such a contraption’.
It is possible to regulate cycle lanes so that people don’t just zoom around irresponsibly. Curiously you don’t seem to consider equivalent risks from cars (can’t drivers act irresponsibly? is it preferable that they have several orders of magnitude more mass with which to injure people?)
The idea is that in such a city you don't need to lug around your children unlesd they're quite young. Children as young as 8 are fully capable of going to school, park, etc... on their own.
With some physical aptitude you can easily go 25-30km/h on a bog standard Walmart bike. On my unrestricted ebike I never pass 32 on a bike lane (if I'm going faster I just go into a car lane). So an ebike limited at 32 is no more or less dangerous than a normal bike. No need to build a car.
Anyways cyclist on cyclist injuries are much less severe in general than car on car.
In terms of traffic flow, I notice that there is a big difference in how terrain affects manual vs powered bikes. I am an avid cyclist, so I say this just to point out that humans tend to be power-limited, while machines tend to be speed-limited. I’ve observed, when my friend and I are out together, that we need to keep more space between us if we are on different modes of power, to account for the abrupt changes is our relative speeds when the terrain shifts abruptly.
Is the injury stat a guess or a fact? I wouldn’t have intuitively been willing to hazard a guess either way myself.
Electric light motorcycles replacing cars would be an absolute benefit to everyone. The biggest issue for those is range (density) and getting killed by a car.
In several locations in the US electric bikes are speed-limited to 20-25mph (32-40 km/h). There's no reason you couldn't set the speed governor much lower to match human speeds.
At least where I live (Seattle) if I were to take up biking I'd need a electric assist, since the hills are absolutely massive and steep.
At least in Germany most electric bicycles are limited to about 25 km/h, which is about what normal cyclists manage on straight roads, anyway. It's definitely not unreasonably fast.
There's also the category of electric bicycles limited to 40 km/h, which are handled pretty much identical to motor scooters (require insurance, cannot use normal bike lanes, unless specified, etc.).
Look at childhood independence (or childhood mobility) in car-centric cities vs bike+transit cities. The argument that children are more mobile in cars does not hold up to any real-world scrutiny.
It’s unfair to consider electric bikes as most bike lanes are explicitly not designed for them.
Where do you get this information? Sure they can go faster, but most folks here are decent about things and they sure help going uphill. It means more people can use the bike lanes - notably, people without the strength to go uphill.
an 8 year old is not too young to travel on their own to limited places. If your bike lanes are actually safe, it is safe for them. And realistically, most places let actual children ride on the sidewalk.
Kids too large for a baby seat can generally sit in a pull-behind wagon.
In the EU electric-assist bikes (which are the ones allowed in bike lanes) are limited at 25 km/h. Sporty normal bike commuters regularly are faster than people on them.
i'm speaking from a european city (400k inhabitants) perspective, where everything is rather crowded compared to the american suburb commute.
> A majority of the population cannot use bicycles for long trips
well, bicycling _in the city_ is usually meant for short trips, but 95% of my trips are short trips of less than 10km.
> Only healthy citizens with an excess of time and energy are able to use them for trips
excess of time: on my commute i'm on average a lot faster by bike - no gridlock, no search for a parking spot
energy: carbs are cheap
healthy: cycling improves your health and fitness follows an S-curve. even if the ride is arduous in the beginning, it quickly gets easier
> The elderly, children
personal experience (biased): compared to driving, a disproportional amount of cyclists are elderly or children
> those with heart conditions, asthma, or many other health conditions
i don't know about that. a bike courier i know uses an asthma inhaler, but i haven't asked him about it.
> and anyone needing to transport anything heavier than their own body
you're right that there's a limit, but i can impose those same arbitrary limits on cars: "what if i need to transport X which doesn't fit in a car?"
> Creating exclusionary space for bicycles is the opposite of progressive policy and efficient urban design.
it's a safe space for cyclists who are not able or willing to ride on the road shared with drivers. i usually don't mind riding on the road, but as soon as i got my toddler in the trailer i tend to get rather touchy about safe cycling infrastructure.
i'm not sure what you're arguing for though. are you arguing for motorized individual transport, because the disabled, elderly, toddlers prefer cars? or public transport?
Public transit. A bus lane will carry many more people more efficiently. Cargo and emergency vehicles can also use this lane if necessary. Dedicated bike infrastructure such as protected bike lanes can generally only be used by bikes and other small vehicles.
I'd be very happy to see dedicated bus lanes in my locale, along with bike routes. In my vivid imagination, the buses would be synchronized with the traffic lights, allowing them to move through town quite efficiently, even with stops.
Ours is a mid sized town, and we don't need a lot of dedicated bike lanes. For the most part, the cyclists find routes through neighborhood streets where there is minimal car traffic. Cars use the faster trunk roads. The only dedicated bike infrastructure are longer bike paths built on old rail lines, and in some areas where there is just no convenient low speed bike route such as a narrow artery between two lakes. And the long bike paths are at least partially if not primarily intended for recreation.
This sounds awesome, but I'm guessing can only work if there are few buses? (I live in London and can't imaging such an arrangement being even remotely workable around here.)
The trams in Croydon work this way. There's an induction loop on the tramway which detects an approaching tram, and tells the traffic lights to change to allow the tram to cross the road/junction.
bicycling and public transit complement each other (almost) perfectly. i don't see why you're advocating for "dedicated public transport lanes instead of bike lanes" as opposed to "dedicated public transport lanes and bike lanes".
> A bus lane will carry many more people more efficiently.
i think it's close. yes, you can cram more people on a smaller space in a bus, but the bus - and upping the lines frequency if necessary - is comparably expensive.
the big difference is, of course, personalized transport.
Yes, this. You bicycle to public transit, then either safely park your bicycle or load it onto public transit.
OP is attempting to find an opposition where none exists. Most people are not so wrongheaded, and where you find an advocate for safe cycling, you'll also find an advocate for public transit.
Not everyone can drive: We still have roads. And honestly, I've met a few folks that couldn't drive but could bike if it had 3 wheels (physical limitations) and with the electric bicycles, the folks that cannot do it are becoming less and less. In any case, it is nearly impossible to include everyone in everything: Without this, more people are in harms way OR excluded.
Bicycle lanes are great for powered wheelchairs, and folks can go faster than foot traffic then. You can get such things covered for winter (I see it here in town). So long as you maintain them like you do roads, they can be available all year.
Around here, bicycle lanes are generally alongside foot traffic and have shortcuts. Busses are available, though.
I live next to a urban high school. In the before “school from home” times they installed a bike lane, then immediately had to install a lot more bike racks. These kids can’t drive and if they could there is no parking lot. I think it’s great.
I live near an urban elementary here in Norway: So many bikes are lined up at the racks outside the school and it seems the kids have fun afterwards while going home (usually in groups).
Bike racks are an often overlooked part of having bikes and I wish more places had them! If you cannot keep your bike safe while at work or the grocery store, it doesn't work.
I do suppose it really should say, "good, well-designed bike lanes" but as it goes, I'm just now realizing it and it is way too late to change.
The bike infrastructure I've seen in the US has been low or lacking entirely, but I really am never sure how representative it was: I lived in Indiana in small to medium sized cities. In the smaller ones, it really wasn't unsafe to just ride on the road anyway and bike lanes weren't so necessary. At least one city had a walkway/bikeway where railroad tracks used to be and lanes around the river, which made biking decently convenient.
You're gonna call riding a bike, instead of a car, ableist and classist? Great, let me just go get an expensive to own, expensive to maintain, expensive to operate vehicle so I can really stick it to the rich.
Can you better explain the ableist remark? It sort of comes off like you're being mocking.
Show me one example of a city that is reducing transit in favor of bike lines and I might believe that's a legitimate concern. Almost always, cities that are looking to add bike lines are also looking to expand transit.
Bruh. This is just incorrect. I am fat and asthmatic and commuted by bicycle all during college in Athens, GA and and by e-bike for about a year in Atlanta, GA. Cycling, especially e-bikes, is extremely accessible even for quite unfit populations. With my e-bike, rack, and paniers, I can do weekly shopping trips no problem as well.
Besides that, it gets cars off the road meaning that the disabled/unhealthy population you care so much about will have higher priority access to car infrastructure.
Thank you for sharing this. I just wanted to add that cycling helps improve fitness, and unfit populations could become fitter if they chose to cycle. This brings about multiple benefits and is not the case with other transport modalities (car, bus).
This is wrong on so many levels. I’ve spent years biking in the Netherlands. People from age 7 up into their 70s ride their bikes regularly and safely - so safely that bike helmets are a total rarity. People ride ebikes and even gas mopeds on the bike lanes, and it all works out just fine. People drive electric mobility scooters in the bike lanes. People in wheelchairs have special adaptors that let them pedal with their hands and use the bike lanes. Your statement that most parents are physically incapable of moving their young children on bikes is proven false by the tens of thousands of Dutch parents who transport their kids in bike seats every day.
Bike travel is about as egalitarian as it gets. You can buy a serviceable bike for a couple hundred dollars, with basically no extra costs - compare that to a car, or even a bus pass, and it’s a screaming deal.
> People from age 7 up into their 70s ride their bikes regularly and safely - so safely that bike helmets are a total rarity.
Bike helmets are designed to provide some degree of protection in simple falls, meaning falls that are caused by lots of control as opposed to a collision with another object like a motor vehicle.
I've heard that older Dutch cyclists are dying due to head injuries that could be mitigated by using a helmet or riding a trike insured of a bike.
There have actually been studies done on this. The estimate I’ve seen is that for every year of life that would be prolonged by mandating helmet use in NL, 25 years of life would be lost from the loss of exercise by people who don’t take bike trips because they are put off by helmet wearing. This is a real thing that has to be taken into account.
The other interesting stat is that an hour of bike riding in NL carries approximately the same risk of head injury as an hour in a car in the USA. So, should we make all car passengers wear helmets? It would make them safer…
TBH, I'm not in favor of requiring helmets, but given the fact that balance does tend to decline with age, I think that recommending that older cyclists ride trikes instead of bikes would be a good idea. Falling off of a trike is less likely.
Would helmets in cars make them safer though? It's a different risk profile; I don't think you tend to fall out of your cars and hit your head?
I can't find any stats of prevalence of various types of injuries in cars, although it does seem to be a thing to get brain injuries in cars (whether that is due to impact or neck/head stopping I don't know)
I think the reason more people don't use the kind of bike lanes we see in the United States is that they're not safe. Cycling in the U.S. means riding on roads with vehicles that aren't expecting bikes and that can easily kill you if the driver makes a small mistake. If you're lucky, some parts of that route will include a painted bike lane, and if you're really lucky that bike lane will be separated from deadly traffic by a physical barrier and won't be adjacent to a line of parked cars that may open their door at any moment and hit you. But neither of these "luxuries" are common in the U.S. or in most countries - bikes are simply an afterthought.
In that environment, it's no wonder that only more physically fit people will be likely to cycle, because you need some strength and agility to quickly course-correct and avoid danger. But these things aren't inherent to riding a bike. If sidewalks were a painted lane down the middle of the street people with disabilities wouldn't be safe walking on them (just as they are sometimes at risk on crosswalks), but that doesn't mean pedestrian infrastructure is ableist. As someone with a disability that prevents me from driving, I'm glad I have good pedestrian infrastructure in my city, and what passes in the U.S. for great bicycle infrastructure. But I wish I didn't have to share the road with cars.
> I think the reason more people don't use the kind of bike lanes we see in the United States is that they're not safe. Cycling in the U.S. means riding on roads with vehicles that aren't expecting bikes and that can easily kill you if the driver makes a small mistake.
The problem is that bike lanes are retrofitted on roads that are really not wide enough for another lane. As a result, you get a substandard width bike lane and more narrow general purpose lanes that don't slow down traffic.
This results in close passes and less margin for error.
> if you're really lucky that bike lane will be separated from deadly traffic by a physical barrier
The problem with physical barriers is the fact that they don't continue through intersections. Cyclists are lulled into a false sense of security and don't pay attention to traffic as they approach the intersection. Motorists are likewise not paying attention to cyclists on the barrier separated path. Then both are caught by surprise when their paths cross.
The best option is to just take the lane and follow the rules of the road for drivers of vehicles. You get noticed and you don't have conflicts at intersections. You don't need to be physically fit to do it (other than be physically capable of riding a bike).
> The best option is to just take the lane and follow the rules of the road for drivers of vehicles. You get noticed and you don't have conflicts at intersections. You don't need to be physically fit to do it (other than be physically capable of riding a bike).
Most people won't be comfortable doing this for the simple reason that they'll be going slower than surrounding traffic and it will piss of drivers, which is scary when you're on a bike and they have two tons of metal right beside you. If the safest way to do something is mildly terrifying and generally viewed as antagonistic, we can't be surprised that most people will avoid doing that thing.
I've really been inspired lately by watching the videos on this channel about urban design in the Netherlands: https://youtube.com/c/NotJustBikes
I didn't realize how much urban cycling raises my blood pressure until I watched this video that compares a journey in Canada to a journey in the Netherlands, it's hard to imagine cycling being so safe and easy outside a college campus: https://youtu.be/M8F5hXqS-Ac
> Most people won't be comfortable doing this for the simple reason that they'll be going slower than surrounding traffic
People, in general, aren't comfortable engaging in an activity they don't have experience with. A motorist who drives a car for the first time in traffic is not comfortable.
Comfort and confidence come with experience.
> it will piss of drivers
Based on first hand experience riding a bicycle while taking the lane in traffic for more than a decade is that it's a rare occurance. My estimate is that someone shows their frustration maybe once every several years.
On the other hand, riding near the edge or in a substandard width bike lane will result in frequent close passes and frequent close calls with turning traffic (weekly, if not daily).
> which is scary when you're on a bike and they have two tons of metal right beside you
The same rationale could apply to motorcyclists versus motorists in cars, SUVs, and pickup trucks. In fact it can even apply to the latter versus bus drivers, dump trucks and tractor-trailers.
But the way that traffic consisting of vehicles that have different sizes, masses can all share the road is because the drivers follow the same set of rules. It also works for cyclists.
> If the safest way to do something is mildly terrifying and generally viewed as antagonistic
Based on first hand experience, I don't think these assumptions are really valid. If that were the case, then we wouldn't see cyclists on the road at all. But, there are many locations where cyclists ride on the road without bike lanes or separated paths.
> we can't be surprised that most people will avoid doing that thing.
Whether most people will engage in a particular activity should not affect the best practice from a safety and efficiency standpoint. For example, the motorcycle safety foundation focuses on bike handling skills and defensive driving. They're not trying to get more people to use motorcycles for transportation, nor are they trying to get infrastructure built specifically for motorcyclists on existing roads.
Similarly, we should focus on education for cyclists in terms of how to use the existing road network to get to their destinations rather than focus on piecemeal infrastructure that really makes things more dangerous for them by reinforcing bad riding habits that are unsafe.
The Embankment in London (Westminster to Blackfriars) lost one of its four vehicle lanes for a kerb separated two way cycle lane. It carries more traffic than the four vehicle lanes, but looks far emptier, which invited much complaint at first. I’m glad to see TfL are still building more cycle lanes, various types to suit the roads used.
It is surely true for the density part. However I have now seen bike lanes that are two years old that would be efficiently « unjammed » by doubling.
Another great aspect of bike density is that when you double the lane you allow way more traffic. When you are slow and small, you don’t need much space to overtake a slow electric bike.
4 years ago, few bike lanes and very few bikes. Detractors of the newly created ones were arguing about the ressource waste.
Today it is one continuous line at rush hour and some lanes are completely jammed.
I am not an expert, but what a change. The pandemic may have helped but it is a true transformation. Many people who would have never bike in Paris a few months ago now bike daily to commute.
It certainly took more than just laying lanes, planning and choosing the right places to create lanes has certainly a lot to do with it. But once the main places were connected by safe lanes, it began and never stopped.
Millenia-old super dense city certainly helps too, nonetheless many thought it would be impossible.
Would probably be harder in a less crowded place.
The only difference here that I think is really meaningful is that bike lanes generally aren't already fully built out and at full capacity.
If we didn't believe bike lanes would induce demand for biking we wouldn't say "let's get people out of cars" as one of our major reasons for adding bike lanes. We accept - even hope! - from the start that more bike lanes will cause more biking. It has upsides compared to car commuting.
But because we don't have an already saturated, congested network of bike lanes, we aren't going to be hitting the limits of "why didn't adding more parallel bike lanes reduce the amount of congestion?" - the congestion just doesn't exist, and we'd have to have a LOT more biking to make it exist. And if we get to that point, it's a big win! Fears of future bike traffic should not stop us from building bike lanes.
Everything else about why "they're different" seems like handwaving.
The point of the article is that bikes, by virtue of their limited speed, don't suffer the feedback loop of less density that cars do. The distance you can travel by bike in half an hour is not influenced that much by infrastructure.
My bicycle commute (and walking and running commute, depending on weather and mood) is one of the highlights of my day due in part to minimal waiting for other vehicles.
Separated rail or river trails are definitely a plus for bike commuting. But infrastructure parallel to roads with frequent intersections and mid-block driveways isn't really that much different than riding on the sidewalk (with all the hazards that come with it).
This may be true in suburban USA, but at least in European cities, sidewalks are used by pedestrians. You have to be alert riding a bike, but it’s a far cry from attempting to weave through foot traffic. The narrower roads also allow for quicker traffic light cycles, which is nicer than waiting a few minutes to cross your average suburban US arterial.
One summer my commute by bicycle involved a route that regularly had a certain degree of bicycle congestion, enough that at one choke point in particular we were completely saturating the road (not just the bike lane, but the car lane heading in the right direction too).
In that portion my speed was probably halved, congestion definitely does have an effect at high enough volumes. If more roads in the area had bike lanes this wouldn't have happened and my commute would have been faster (and more pleasant, riding in bicycle commuter traffic is somewhat stressful since everyone wants to go at different speeds). On the other hand if the same number of people were in cars in the same amount of space traffic would definitely have been much slower.
I noticed on crowded bike days in the city it’s a little like being on a conveyor belt. You can try to ride a little faster but because of traffic lights and other riders there is just a speed you are going to be limited to. This is the same as driving.
I mean, no for two reasons. Traffic lights grouping people as you say, but also the bottle neck causing so people commuting on bikes to use this road wouldn't have existed if the other roads in the area were also designed to accommodate bikes.
On the flip side, this isn't a city where a large percentage of people commuted by bike. If you turned all the people commuting by car and public transits into cyclists it wouldn't surprise me to find out there were still areas with congestion.
Infrastructure tends to be constrained and will likely limit one's speed to the speed of the slowest cyclist ahead, since there's no room to pass.
The other issue is that infrastructure doesn't take downgrades into account. So, while it can be safe to get up to speeds exceeding 20 mph (30 km/h) while in the center regular travel lane with a significant space cushion due to it's width, such speeds are hazardous with infrastructure. This means that with rolling terrain, the average speed will decrease significantly because one cannot safely travel at higher speeds on descents to make up for the time lost on ascents.
A key analogy that went unused in the article is the Red Queen's Race: "it takes all the running you can do to stay in the same place" applies to car traffic precisely because cars are large and powerful and are persistently required to make slow turns and smooth stops relative to their size - think of all the roads where you have to carefully inch out, keep deliberate pace and stopping distance, and so on. Spaces that are "for cars" correlate to spaces that are unsafe "for people". If you add more than a small topping of car traffic to a road, they will impede each other. Therefore, to make large numbers of cars move quickly you have to add disproportionate amounts of car infrastructure, which creates car-centric land use patterns, which inhibits alternatives and makes cars the default by dint of being the smallest unit that can safely use a road. "If they get bigger, I must get bigger too" is applicable thinking for someone who wants to feel safe on the roads.
If you reduce the scale, the speed, the headways, you have greater ability to adjust. While car pileups are expected, bicycle pileups are a thing usually only seen in races when the limits are being pushed. Ordinary bike commuters can navigate safely without rules when given a mixed bike/pedestrian space of sufficient size. Bikes don't get bigger to feel safer. The resulting infrastructure scales better for the cost, and the Red Queen's Race is averted. When bike lanes reach capacity, the failure mode is crowded-stadium, not stand-still freeway. Traffic slows down gradually instead of creating roadside bloodbaths.
Transit does experience more of a headache from induced demand pressure since it also uses large vehicles, and the entire trip experience is contingent on not holding up that one train or bus - while Tokyo's system works, the crowding is notorious, and the train stations have sizable footprints. But as a collective effort, it can also be much more coordinated and deliver useful results from capacity increases.
It also doesn’t illustrate the real scale of space required to operate each vehicle. A car needs several car-lengths of space between them. Bikes can be operated more closely together. At speed all of these vehicles scale up to more space differently.
In the US road engineers go to strategy for safety is to just make the roads wider. When drivers feel safe they start driving faster than the speed limit. Those roads were designed to be "safe", not fast, meaning high speeds are more likely to lead to worse accidents.
"A car needs several car-lengths of space between them."
The distance between bumpers actually cancels out (actually it comes out in the car's favor). First notice that in the picture the cars are almost touching, so clearly you mean in fast moving traffic.
In fast moving traffic the carrying capacity of a lane is equal of the inverse reaction time (typically engineers use a large margin of safety and 2 seconds is used -> 1800 cars/(lane hour)).
For bikes, since they travel more slowly, you have to add the time it takes to travel their own length. So the carrying capacity of a lane is 1/(reaction time + length of bike / speed of bike).
The "several car lengths between them" is literally space that exists only because cars have generated themselves by virtue of going very fast (since fast moving vehicles get to where they want to be quicker and therefore get off the road to make space for someone else).
This doesn't mean that cars make sense in dense cities. They don't.
This doesn't means cars don't take more space by virtue of being longer in slow traffic. They do
But it does mean that, if there are "several car lengths between them", they are in fact operating in a more space efficient regime.
That's context dependent. Where I live it's not a problem that a car takes up space (my car is parked in my home's basement).
Where I typically go to it's a relatively minor problem - most places I go to only need 4 to 5 places to park cars.
Work is in the middle of nowhere, again not an issue except that the government employees have reserved the lot by the building for themselves despite it being large enough to house the contractors as well (the govt. employees want to ensure they get the spots nearest the building).
Should the city of Rome have cars? No. But we don't (nor can we!) all live in a small European city
Here are the originals. What's interesting is that the car picture isn't among them in that form. I don't know whether it has been digitally edited, or they've taken another picture as well. However, the car picture looks like four rows with more than 15 cars each, but it's hard to tell as it gets fuzzy.
Static space. In the real world people exist in both space and time. Ten people who complete a journey at 100mph take up the same time-space (ie road) as one person at 10mph. Someone at 1mph takes up as much road as 100 people on the same journey at 100mph.
If the question is how many people can we shove through a pipe/tunnel/travel network, speed is as much a factor as physical size. Bikes and cars both take up massively more time-space than trains or busses. But pro-buslane voices are rare these days.
That’s all reasonable analysis if you’re optimizing for shoving people through a space. Most people are trying to go places and do things. The bottleneck isn’t just harming transit completion, it’s harming the whole purpose of being in motion in the first place.
The definition of a bottleneck is a place where we are at a people-shoving capacity, the place where congestion is born. If people-shoving isnt a priority then there isnt really any bottleneck that needs dealing with.
In front of a moving vehicle is an amount of that pipe/tunnel/travel network that is basically unusable by people who aren't inside that vehicle. As the speed of the vehicle increases, so does the length of that unusable space.
If I'm a pedestrian who needs to cross a road, or a driver who wants to turn on to that road, it's equally busy if there's a 10mph cyclist half a block away, or a 100mph car 5 blocks away.
Again, time. The faster vehicle occupies more road but for a shorter time. That fast car down the road and that closer/slower bicycle both occupy relatively similar amounts of roadway in comparison to multi-person vehicles like busses. The fastest way to move people down a given lane is to cram them into trucks army style and then drive slow enough that each truck leaves minimal time between each. A lane can then handle a 50-person truck every 5 seconds, or 10 people per second. That's far more than can be pushed through on individual bikes riding in pairs.
This is assuming a chink of road in isolation. There's also intersections, vehicle separation, signaling, and other needs that take up less space-time on a bike than a car. Perhaps less-so than a bus, but we would probably need simulations to say more.
Of course, but for a discussion of bottlenecks signalling isnt an issue. Putting an intersection at a bottleneck is just stupid. Thats why bridges fan our thier roads on either side.
Parking is a whole other problem but in cities where everyone has to commute in/out of an area the bottleneck is more often the roads than lack of parking spots. (Parking can be built up/down while roads are built in 2d.) Underground parking structures (3d) also use space that is generally unusable otherwise. Few offices are permitted deep underground due to fire codes.
Not so, huge numbers of cars in NYC are just driving around looking for a park! If you raise the cost of parking fewer will drive, so the two are closely interconnected.
Because NY has chosen to not have spots, to build other things. There is plenty of physical space if every building dug out an underground car park during construction.
That’s assuming your traffic is free flowing. In city traffic it’s not at all unusual for bike to match or exceed cars’ speed. For example the average speed of traffic in inner London is less than 12mph (in the centre its more like 7).
Yeah, I got an electric scooter a few months ago. It’s always fun going along the separated bikeway alongside one of the big six to eight lane freeways coming in and out of the middle of the city I live in, and at some times even at 25 km/h still going faster than the car traffic!
In the part of the Netherlands where I live it's not uncommon for a bicycle to be faster than a car at reaching a destination, because it's very dense in the north so your destination is likely in an area where cars can't go faster than 30 and you on a bicycle would go 20 but are far more manoeuvrable and can take shortcuts and don't have to park, additionally you don't get stuck in traffic on the bike lane because you can pass people as people are not allowed to cycle with more than two side by side and due to the quick acceleration people move aside if you ring your bell. That's why in the dense north and the cities it's often faster to go by bicycle and probably why the electric bikes are a popular alternative to cars for people with limited physical ability.
Elsewhere less dense it's probably a different story if you have to travel a few kilometres over a 60 km/h road to reach your destination.
Not only the Netherlands; even without dedicated cycling infrastructure, cycling will be faster for distances under a couple miles for pretty much any walkable town or city. Deliveroo uses bicycles extensively.
It’s the same here in Washington DC: bikes are faster for most trips, especially e-bikes, unless you’re going all the way across the city (10mi square) on a handful of routes and have parking available next to your destination.
That last part is something which drivers usually leave out in their travel time estimates: off-peak, a car can often go faster to the general area but the time needed to find parking, pay, and walk back usually cancels any savings several times over.
So imagine two hundred people on bikes on a mile of bike lane and twenty people in cars on a mile of freeway. Both are the same freeway width. Just hold the thought of that enormous bike lane for a second. Then go ahead and tell me the same amount of free time-space is available for crossing in both cases.
So let's say that's 10 cars and 200 bikes (being generous, usually cars have only one person in them, and also bikes esp. with children in biking-heavy countries have more than one person carried by them).
If they are evenly spaced, there will be a car every 0.1 miles - and each car is going 100mph according to this thought experiment. This gives 3.6 seconds to cross between 100 mph cars that probably won't swerve to avoid you and may careen out of control if they do.
Meanwhile, there is a bike every 26.4 feet, and you have 1.8 seconds to cross. 10 MPH is speedy for a bike, but they have to only slightly adjust to avoid hitting you if you make a mistake (and are about 1/5th the width if not less).
you are right to bring up speed as a factor. one interesting study found subway escalators are more efficient when people stand close compared to walking up! Space trumps speed in this case.
In urban environments, cars have a low average speed (e.g. in London UK it's around 14mph) so I think space will dominate here too.
Also remember that as speed increases, so does spacing for safety reasons.
Cycle infrastructure should be built by taking space from cars, not busses.
Please don't forget that those vehicles (except for the public bus) are static all day except for an average of 45~60 minutes. The car does take up far too much space for it's limited usage.
I think there's room for both. The advantage of walking or taking a personal vehicle (car, motorcycle, or bike) is flexibility: you can depart at any time without waiting for a transit vehicle to come along.
This is why congestion is so exacerbated with cars. All it takes is a slowdown in one section of the road to ripple out the effects of the reduced throughput further back.
Yeah it goes both ways. Not only does a fast car consume less space, a slow car consumes more space. So once you have stop and go traffic the amount of space a car consumes for the sake of safety is just absurdly large.
That's not how the math works out, it isn't linear. The distance it takes to stop anything is dominated by a term quadratic in the velocity. Thus the average safe traffic density decreases with the velocity like v^-2. Since the throughput will just be the velocity times the traffic density, throughput roughly decreases proportional to 1/v. (In the zero velocity limit, physical size terms would dominate, so you don't get infinite throughput.)
So if you do the math, bikes take up less time-space, or said better: achieve higher throughput. They are multiple times more dense at their travelling speeds. The only real way out of this would be to travel at unsafe distances.
You assume single passenger vehicles. Do the math again for a 50-person busses. Compared to that, bikes and cars are relatively similar. Even four-person cars, with say 4 seconds between them (one person per second) better single-passenger bikes traveling in pairs. Bikes rarely ever maintian such separations, genrally leaving 7+ seconds between pairs when at speed due to bikes having reduced stopping times from top spèed.
It may be a reasonable assumption; what are typical vehicle occupancy rates?
Also, a bicycle-majority traffic mix wouldn't have to conflict with the presence of high-passenger-capacity buses.
That may be true that cars can have shorter time-distance separation, but I think there's a gap in the modeling there with regard to group travel:
If you have a four-passenger car and compare that to the same group of people traveling together by bicycle, the time-distance separation factor disappears.
UC Davis alumnus here. Bike lanes at full capacity work much better than motor vehicle lanes at full capacity. You may have to wait to join the traffic, but since you need a smaller space there’s less wait time. Roundabouts are very efficient. Accidents do happen, but are far, far less deadly and can almost always be cleared in under two minutes.
Just watch out for freshmen at the first rainstorm. You can tell them apart by their freshman stripe — the result of not having a rear fender.
While I believe the logic in the article is sound, I think it missed the mark on what actually transforms cities in such a way.
It's not the cars - they're just tools. It's the insatiable appetite for living space.
There's a trend in the city I grew up in(Warsaw, Poland) that started over 20 years ago and continues to this day - people grew tired of living in crammed, Plattenbau apartments, so they moved to smaller towns(in part inspired by their notion of how Americans live) adjacent to big cities where all the jobs were. Additionally at that time interest rates were so high that this was an option for those who couldn't get a mortgage for an apartment.
Cars followed, but not everywhere. Places close to railways were an exception, but only up to a point, because over time commuters exhausted any spare capacity there was, so the remainder had to drive and bear the not insignificant costs of that. In the meantime a highway was built, but that didn't help for long.
Was Warsaw hollowed-out by this? Hardly. What happened instead is that it started cannibalizing smaller (but still relatively large) cities.
I fail to see why induced demand is a bad thing. Faster CPUs also cause induce demand as then software either does more stuff or does stuff less efficiently. That does not mean the we should stop trying to make more powerful CPUs.
Even with a constant amount of congestion, it means that more people are using the roads which means that having the road is optimizing for people’s choices.
> In 1941, your kid might have walked 15 minutes to the neighborhood school. In 2021, you drive your kid 15 minutes to school. Oh, and this isn't your choice: they tore down the old school and replaced it with a parking lot.
> In 1961, you might have biked or driven a few blocks to a corner store for milk and eggs. In 2021, you drive 3 miles to Kroger for milk and eggs, and there is no corner store. Has your utility increased? Or are you mostly just consuming more resources?
I would argue that utility _has_ increased; It's just that the market has re-organized itself such that the increased utility comes in the form of more flexible locations for houses and businesses rather than in the form of decreased commute times. One grocery store every 5 miles costs far less to maintain than 100 corner stores distributed evenly throughout the city, and you can get more house per dollar buying a house in the suburbs rather than if everyone were competing to buy housing smack-dab in the middle of a city.
I think perhaps a stronger version of the author's argument would be to point out that road use is an externality. Building more efficient roads comes at a significant cost, but road users don't pay that cost in a manner proportional to their use of those roads. Therefore the market does not factor in road construction costs when deciding how to organize cities, only costs of the transportation itself like commute times and gas usage.
I dislike the term "induced demand" for the same reason the author gave. "Induced demand" is really just "demand"; all economic systems work that way. The only thing different about roads is that our current system of road construction funded primarily by income taxes makes road use an externality.
A grocery store every 5 mile costs a ton of fuel to maintain as clients need to drive in. It requires much more roads to be built and bigger ones too. It's not clear at all that it's more efficient when considering the whole picture
> One grocery store every 5 miles costs far less to maintain than 100 corner stores distributed evenly throughout the city.
I'm not at all convinced that this is true. It would make sense in a vacuum, but there are a lot of negatives from the road infrastructure necessary for large driving-only grocery stores.
Dense cities have lots of smaller grocery stores rather than a few large ones. I'm sure there's a reason for that.
In San Francisco, as far as I can tell, there are lots of small grocery stores, a fair number of medium sized ones (Trader Joe etc), one big one (Costco), and no really gargantuan ones. Maybe I'm not shopping in the right places though.
San Francisco is not what I would describe as a "dense city".
It does appear to be true that grocery store availability in San Francisco is just a straight downgrade from what you can find in e.g. much of the rest of the Bay Area. But that's a choice by San Francisco, not some truth about cities.
And it’s a great mix. I can do 99% of my shopping for food and liquor at the corner store. When I need to buy for a huge dinner party, or find some rare ingredient/bottle, I can ride a few miles on my bike to the larger store.
Okay, maybe dense cities were a bad example. Obviously density makes a larger number of stores per square mile more viable than it would be in a less dense area, even if you have a highly effective transportation system. My point though is that, all factors considered, our current city layout actually is close to optimal under the assumption that road construction is free.
The problem of course being that road construction is _not_ free; we've just created an incentive structure that causes the market to behave as it it were.
Based on what I've read, it's not that road construction is expensive, it's that ongoing maintenance of roads and connected utilities is quite expensive.
Induced demand is literally just latent demand that wasn't met and latent demand that wasn't met is just demand.
The only difference is the appearance that the demand is truly endless. Building roads is a subsidy to cars. People don't pay for the roads they get for free. The optimal strategy becomes driving because public transport is "inconvenient" because the alternative to bad public transport isn't better public transport, it's more cars. So, now the entire city wants to drive. Of course, the problem with that is that cars are such an inefficient means of transport that it's impossible for everyone to drive. The fairy tale of induced demand is born.
yes, but the fixed and variable parameters to "use" and "density" are different.
And luckily, except for outside Amsterdam Centraal and a couple of other places, it doesn't matter: The fixed and variable parameters of the model are far above where we want to be and far above where we would be, if we reduced single occupancy car-type vehicle use.
If we include the crazy, semi-fatal Dutch microcar, I think we might get to the worst of both worlds: thousands of people old and young driving microcars like they are in Legoland on a toy road, but the road isn't toy.
I think this covers a lot of good points and I'm happy to see it, but the final section seems like a just-so. I've wondered if the difference in bike-induced-demand=good;cars=bad follows these lines:
- Roads/cars often leads to the phenomena of something like grid-lock. A network might be able to throughput 100 cars a minute when only <=100 cars are trying to get through, but try 101 and it starts dropping: If 120 cars attempt passage at once, congestion actually causes the throughput to drop to like 80 (think of those backward-propagating traffic-wave videos). If 150, throughput drops to 70 etc.
- You can add more roads/highways but if it doesn't address certain chokepoints, that throughput will still start descending at some point (though maybe a bit higher now like 110 cars/minute).
- Sometimes you can address the chokepoints, but after some expansion the remaining chokepoints are essentially having the buildings and city intersections themselves, at which point you can only address the bottleneck by rebuilding buildings further apart, which leads to a cycle of worsening pedestrian access, local-depopulation, and more cars.
- And then finally, maybe bikes are different in that they are small and agile with a congestion-failure-mode of being walked. It's hard or unlikely to get to a bike usage level that would lead you to want to move buildings very far apart to support them.
- Or maybe bikes are just simply so small that the preferred distance between buildings anyway (for sun light, privacy) can support most realistic biking numbers (which would be limited by density limits anyways: elevators only practically go so high, commuting biking trips can only be so far).
- Ultimately I wish there as a bit more explained here, maybe by someone that designs traffic/city simulations if that's how the best cost/benefits are tested now. It's really confusing that urban planning advocates concentrate on the un-improving car-trip-time/congestion KPIs like it's a dunk when it really seems some throughput-capacity utility metric would be more important.
Given the cost of housing in major cities, and the relatively lower cost in far away suburbs, doesn’t the argument about development patterns imply that building highways will help with cost of housing in the medium-long term?
Induced demand is really interesting, and most people aren't aware of it.
It applies to things like traffic, and yes, housing.
If building more housing lowered rents, I could finally afford a place in NYC, or LA, or SF. Unfortunately it doesn't work that way. But I wish it did.
Induced demand is a terrible argument anyway. It's like arguing that capitalism is bad because material wealth induces demand for material things like homes and cars and good dentistry, etc.
And like, sure, on some level that's kind of true and you can argue this but it completely misses the point that giving human beings the things they want - safety, privacy, freedom, mobility - is generally considered a good thing and the lack of it is called poverty.
It’s all about what you want to encourage. Inducing demand by improving roads has few positives, and after a while can cause more congestion than before the road was improved! On the side, it causes more pollution (until most cars are electric), is more dangerous for pedestrians and bikes, is space inefficient, etc. etc.
So cities should want to induce demand in other types of transport (trains, busses, bikes, walking) and try not to induce demand for cars.
Given that over a long enough timeline and in the aggregate humans are rational and humans also want to minimize commute times, it only makes sense that the average commute time across all substitutes converge.
Thus, if you wish to decrease your commute as a driver, the best possible strategy is to advocate for increased alternatives.
"Europe’s super bike highways must have an impact on where people choose to live."
What I'm seeing in a city with growing bike infrastructure is the increased attractiveness of city homes which are "mid-distance" from jobs i.e. places which are too far to be walkable but within biking distance - if you have to use a car anyway, then you might as well go a bit further and get a suburban home instead, but biking augments public transportation in allowing a bit larger "dense city" instead of a lot larger suburban sprawl.
I utterly despise the “induced demand” conversation.
Will building more lanes “solve” congestion? No! Will building more lanes allow more people to get to more places? Yes!!!
Latency and throughout are two different metrics. Building more road does not necessarily reduce latency. However it does increase throughput. This means more people have more access to economic opportunity; and that’s a good thing.
Even as a cyclist, when I hear of new bike lane construction, my feelings on the matter are "meh" or even negative. I think we should instead just normalize cycling among the cars (mostly by educating drivers, who either get pissed or are too cautious to pass even when they have plenty of room). Bike lanes just create the mindset that bikes should be separate traffic, and screw you over as soon as you need to take a left (now you need to merge into the cars on your left instead of already being between them).
I rode my bike across the country and my favorite city for cycling is still Cleveland. Not a whole lot of bike lanes, but wide enough roads and flat terrain. And the only time I was ever struck by a vehicle was when I was riding in a bike lane (because they were trying to turn right).
Surely not every road or destination is going to have bike lanes, so isn't everyone going to have to mix with traffic eventually anyway? Having them in some places but not others is just confusing for everyone involved.
> Surely not every road or destination is going to have bike lanes
Why not? If there’s space for an entire road there’s more than enough for a bike lane or two. With the possible exception of mountain-side single-lane roads where cars barely fit.
The “vehicular cyclist” is very rare. I tried it a handful of times and it felt like an unnecessary risk (ie, death or permanent disability). Way too many distracted or under the influence drivers on the road and all it takes is one to make a permanent life altering change.
US cities need to be built around bikes. There are known models that work (Amsterdam). There just needs to be a significant paradigm shift in American mindsets and dependency on vehicles.
I probably would have agreed with you until I spent a lot of time in the Netherlands. Imagine saying the same thing about pedestrians: “I think we should normalize walking among cars. Sidewalks just create the mindset that pedestrians should be separate traffic.” Yes, to do this right, you need more than just bike lanes down each street that end in normal intersections. You need intersections with separate signals for bikes and cars, with no right on red, with grade-separated crossings at major roads. The Netherlands has done this for nearly every road in the country, and no it wasn’t always thus - it was done starting in the 1960’s as the result of a massive grass-roots people’s movement.
I sort of felt the same way.
But our city’s recently been building segregated lanes on the main central routes and it’s great to see little kids riding in them where before it’s was almost all folks in Lycra - point being it’s made cycling more accessible to people who can’t contend with full traffic.
I think that this cannot be solved by "educating drivers".
Physical separation is needed for lanes with radically different speeds. Today, sidewalks (4 kmph) are separated from cars (40+ kmph). Because of demand of people traveling around 20 kmph, we need another separated lane for bikes and other e-mobility crowd that is able to move approx. in range of 10-30 kmph. Because of safety new lane must be physically separated.
Also, there should be wise to set some speed limit for these lanes, like 30 kmph, for cases when lane is used by hi-powered e-mobility vehicles.
In theory, parts of town where car speed is so limited to speed of bikes (25 kmph?), separation in many cases disappear. Nobody wanna be driving in such speed anyway.
More interesting question (for me) in the context of cities: Do apartments induce demand similarly to roads? That is, does building more and more (and smaller and more expensive) apartments actually fuel the housing crisis in big cities?
I ran into the second effect in a study about traffic I glanced at in a library. It was slightly different, but the result was the same. It went like this:
1) more roads means less space for houses
2) this means people live farther away from where they need to go
3) this means they are more dependent on their cars
4) this means there is inevitably congestion and you need more roads
5) go to 1
My experience is anecdotal but I have observed that in Pittsburgh, the thing that was accomplished by adding bike lanes was to increase traffic congestion on roads that weren't ruined by the bike lanes.
As a cyclist, I believe that bike lanes do induce demand, but there are some important differences.
A single road can attract travels which begin or end far away from the road. So its effect is felt on a larger territory and further away. A road needs only few exits to be connected to other roads.
Bike lanes are more like capillary network than arteries. A single bike lane is almost useless, because it can serve only travels which begin and end in a narrow strip around the lane (maybe a block away). Two bike lanes which are not connected will be used much less than two connected lanes. Even a single discontinuity of the network can make bike travel unfeasible.
So rather than talking about lanes, we should talk about lane networks and their density. And up until certain density the network won't be used much. Only after reaching that threshold we can talk about effects it may have on city development. Similarly, a car road will not generate induced demand nor attract much traffic if it is missing a bridge across the river.
Let say a bike lane attracts traffic if the starting point and the destination are within w/2 from the lane. Let's assume uniform distribution of potential starting and destination points. Then in a city area A, a bike lane of length L will attract only Lw/A potential commutes (within a strip around the lane). There are two important observations to be made: 1) the induced demand is proportional to the length of the network L, 2) parameter w is probably small, likely ~ 200m, so 1 km of a bike lane will have a smaller and more local effect than 1 km of the road. To cover 1 km² of urban area, the well connected network would have to be a grid with the total density of bike lanes ~ 10 km / km².
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[ 2.9 ms ] story [ 239 ms ] threadI’m also not sure why we need to create a false dichotomy between roads and bike lanes. I need driving to shuttle between home, work, schools, and other activities in a time efficient way. I also like biking for exercise and leisure, although bike commuting hasn’t been practical for me when I’ve tried it. Have cities considered elevated bike lane networks on pillars built into highway medians or sidewalks, so we don’t have to choose just one or the other? What about cantilevered elevated walk/bikeways? Or perhaps they can have an underground driving network like Chicago does.
You may also want to read up on induced demand in more depth, because it's about where the demand is, not about how many people are driving cars.
Anecdotally, removing toll plazas in favor of plate scanners and adding bridge lanes to the Goethals Bridge in Staten Island, as well as widening the Staten Island Expressway, has significantly reduced traffic delays and improved safety for several years. There _are_ more vehicles using the road but not enough more to significantly negate the improvements.
https://www.panynj.gov/port-authority/en/press-room/press-re...
To me, the case against improving roads is not nearly as open-and-shut as Strong Towns and similar one-sided policy-pushers make it out to be.
Also, more vehicles are using the road, true, but you have to remember that it increases over time.
Not because of a necessity that any capacity increase must always cause it, but because the decisions of which roads to expand are made by humans who, with the exception of edge cases (maybe the reason for rebuilding was because of the state of the road and increased capacity was a secondary affect rather than the main motivation; maybe corruption led to a poor choice being made; maybe forward looking expecting future demand to increase years later based on other factors like planned new buildings) wouldn't spend money increase capacity unless road traffic has been increasing and looks like it is't about to start trending in the opposite direction soon enough to make expanding the road a pointless short-sighted exercise.
Aka if increasing road capacity wouldn't induce more demand, how likely is it to be in a situation where it's considered worthwhile expanding it?
However, cars are big and takes up a lot of space, especially since people regularly drive sedans that seat only one individual with max capacity for four to five people. This requires a lot of space to support cars.
Of course, you can continue to expand roads. Problem with that idea is that the roads displace other uses of land such as homes and businesses.
Roads increase utility of cars, for sure, but that comes at the expense of everything else.
We saw a dramatic example of this next to the bike path I ride to daycare/work: hundreds of new apartments, restaurants & other retail shops, outdoor public spaces, etc. next to a subway station. This was just part of a retail parking lot which broke 50% usage _maybe_ a couple of times a year. The number of people using the space when up by at least an order of magnitude and it’s a lot more consistent economic activity.
This can only occur when there is sufficient latent demand, or phrased differently, the supply of roads (and sufficiently fungible transit modes) is so insufficient that that moderate increases in supply do not create a surplus. This lack of surplus (traffic) representing an economic inefficiency which it can only be desirable to reduce[0].
What is stupifying is how 'induced demand' (read: building more roads will cause more people to perform economic activities facilitated by transit) is contorted into an argument against building roads.
[0]Until such point that traffic inefficiency is in equilibrium with others. e.g. I can't see Manhattan widening 5th ave anytime soon, but most of America isn't pressed for real estate.
How many roads should we be tearing up[0], and how do we know when we've torn up the correct amount? Since we a. clearly aren't at the optimal amount of roads[1], and b. induced demand argues that we shouldn't be building more.
[0]A clearly nonsensical position.
I don't find it nonsensical at all. My city is actively planning to reduce the amount of normal roads in the city center and introducing more & better bicycle lanes. This is very much needed, since while the central crossing does have (some) gutter bike lanes leading to it, it comes close to suicide to use them. Accordingly, no one does and many use the sidewalks that are already too small for comfort without bikes (the city is in a bad spot there, because it's very space constrained in that place. The roads are badly overloaded in the center and no lanes can be added due to the lack of space).
A nearby larger city would be well advised to remove traffic & lanes from central locations and allow more bike paths and crucially allow expanding the badly overloaded subways with trams (and dedicated tram ways) near the center. Due to various factors, there's no real option to use more tunnels. They have been routinely over the limits for particulate matter and were successfully sued over it.
Now, roads outside of cities are complicated. The larger ones usually can't be easily reduced, but eat a lot of maintenance costs that could go towards higher capacity options (rail). Looking at https://en.wikipedia.org/wiki/Braess%27s_paradox and carefully analyzing existing roads may also make sense. In general, car based travel costs society the most per mile by far. Introducing measures like tolls & car-free cities as well as making alternatives more attractive with shifted spending may reduce demand and thus enable tearing down roads.
The question hinges on a false dichotomy that the only solution to demand is more roads, which is part of what this article is arguing against.
Edit: An obvious but politically hard solution to overloaded roads is encouraging higher density.
Only up to a limit, as I mentioned. They won’t keep “soaking up” supply. People are not looking to drive 24/7. They are looking to reach destinations and spend time there.
> Of course, you can continue to expand roads. Problem with that idea is that the roads displace other uses of land such as homes and businesses.
This seems like a vague argument. Road space displaces other uses marginally. If your population were held equal, then you can build more roads, displace some amount of other uses, and the increased traffic from those displaced wouldn’t be nearly as much as the extra traffic capacity the road provides. If your population increases or usage patterns change, then it is simply “latent” demand that is being met, since there’s an appetite for more travel throughout and increased speeds and all the utility that brings. All of this applies to anything that we can model with supply and demand, including bike lanes.
Because there is finite width for existing roads between existing buildings, and so quite literally, adding a bike lane often requires removing a car lane. It's not a false dichotomy at all, it's literally measured in meters.
> Have cities considered elevated bike lane networks on pillars...
Do you have any idea how astronomically expensive that kind of stuff would be? It's just not even on the table, realistically speaking, for 99.9% of places.
Inside the CBD, they’ve been taking out on-street parking to put in separated bike lanes, and that‘s just as good. They completely removed car traffic from a bridge in the middle of the city also to add an extra bus land and a bike lane, and while some drivers were annoyed, it used to drop you in a extremely congested bit of the city so wasn’t very convenient in the car anyway.
1. https://www.tmr.qld.gov.au/projects/Veloway-1-Pacific-Motorw...
https://www.strongtowns.org/journal/2021/8/24/does-induced-d...
Latent demand: Driving more often because we can now actually get to places when we used to give up trying.
Induced demand: Driving more miles per day because space for the roads pushed each building farther apart over time. Going to larger stores because small nearby stores failed to compete.
I'm not clear what you're trying to accomplish by juxtaposing induced demand with transportation fatalities, when the two concepts don't seem to have any special connection.
As far as I can tell that is exactly the outcome the induced demand folks are hoping for, or something close to it.
And I'm unaware of anyone proposing the elimination of cars as serious policy. At most it's limiting vehicles in parts of dense pedestrian city centers.
People who are generally "left-leaning" on transportation envision a healthy mix between public transportation, cycling, and cars. They simply want car usage to be balanced with alternatives, rather than cars dominating by default.
Virtually everyone recognizes that cars are necessary for a wide variety of uses. They're not going away, so I don't think you need to worry about that.
It does in certain circumstances, like when you'd get 90% of your paycheck if you quit your job, and so people quit. Which is why smart welfare programs provide benefits in a gradual way rather than at a single cutoff -- e.g. how the Affordable Care Act subsidies were designed.
> homeless shelters
Again, it does. Cities with excellent homeless shelters and care literally attract homeless people from parts of the country without. Remember the scandal about cities literally buying homeless people bus tickets to send them somewhere else, to try to address the problem? This is a known issue, and a good justification for why social services funding ought to be provided at the national level rather than at the city level.
> or public transportation
It does absolutely. Entire cities spring up after a rail line is built.
I guess my question to you is -- what are you trying to argue? Induced demand isn't just a property of roads, and I don't know any author who says it's exclusive to roads. It seems like a straw-man you've constructed.
But the concept is often raised in conversations about roads, because many people naively believe that widening a road will solve congestion.
To your broader point, all services work like this to a point; if you first suppose there’s insufficient supply to meet demand, then adding supply can induce more demand. There’s an eventual saturation point for everything though. Tear down all the buildings downtown and replace them with parking lots. There will be plenty of unused parking and no more rush hour as there’s no longer a reason to go downtown.
Right, it's not surprising but highway expansions are often sold as "reducing congestion" rather than the reality of "causing more people to drive more miles with the same resulting level of congestion."
If the actual goal of highway expansions is to make it efficient for people to drive more miles/have longer commutes then there isn't an issue with there being "induced demand," but there may be various reasons why this isn't actually a very good goal.
Highway expansions do have benefits to people who end up moving further out (more affordable housing), but there may be better ways to achieve the goals of providing housing to more people around urban areas by increasing density, or to help people get around urban areas by transit, etc.
This is the primary objection I have to self-driving cars. By enabling people to do other things while they are travelling, self-driving cars raise that limit considerably. When self-driving takes off, so will congestion.
Supply and demand aren't fixed -- they meet at an equilibrium price. There are latent trips that are canceled, change modes, or time-shifted to deal with traffic because of the high cost.
> The phrase “induced demand” is simply a part of the rhetorical war waged by anti car activists.
Induced demand is a standard transportation engineering concept. You might argue that it's been hijacked by the anti-car folks or whatever, but tramsportation engineers and planners who want to build car-heavy transportation systems are aware of and use it. They taught it to me in a very conservative civil engineering department.
Building a Mayo Clinic hospital in Arizona results in more sick people traveling there for care than otherwise would have.
Seems like there are some natural ways this could cause a loop. Now we hire more doctors and train more new specialists. That burnishes the reputation even more. Now more people want to come!
(One thing to note is that it's generally always a localized increase, not an absolute one. The people living in the new suburbs that you built a new shiny road to still would've lived SOMEWHERE in the country. You didn't increase that country's total demand for transit. You just redirected it into "road transit from this particular suburb" from wherever it would've gone in the absence of building that suburb.)
[0]Roads
Just like the people who want to drive somewhere are already there, but the cost of a clogged commute makes it not worth it for them to spend the time, so they do something else.
Bike lanes will not induce much demand if all you have is human-powered cycles. Maybe on sunny days, in flat areas.
Two years ago, the highway nearby completed a 5-year widening project. During that time, traffic was so bad I had to check Google Maps every day to find out which route I should use. Now that the project is complete, I never check Google Maps anymore. I just use the highway without even bothering, as the cost to drive on it is now clearly the cheapest. My life is better in the short term, but eventually more homes will be built, traffic will increase, at some point I'll have to go back to checking Google Maps every day, and they'll start another road-widening project.
I've lived here long enough to experience this cycle first-hand, and nothing has changed logically that would stop this loop from executing again and again. At some point, I'm sure a physical limit will be reached. Either we run out of space, or run out of money, or something else.
Anecdotally, I'm seeing a lot more kids and teens on e-everything
I share GP's concern.
I've heard they are difficult or impossible to get plated (seems like it depends on whos working at the dmv). A lot don't bother because emopeds are stealth (small, look like bike, quiet), so people/police don't bother them unless they're being a total dick
-Bike lanes (and ultimately, bike destinations) have way higher humans-per-square-foot of road / parking lot density than cars lanes. The throttling mechanism on behavior for the car example is ultimately drive time, and new lanes quickly become capacity constrained (first at the interchanges; later at the parking; last in the lanes themselves) in a way that slows ultimate travel back to the indifference equilibrium. The equivalent for bikes tolerates a way higher flow of humans.
-Induced demand for cars is in part a function of the fact that you can (up to a point) drive at any speed, meaning that if roads are added that support commuting in from 30, 40, 60 miles away, that can be a doable commute. There is no amount of development that will create a 60 mile bicycle commute. Here, the demand induction mechanism with travel lanes and housing is reversed: you need convenient housing to drive the demand for bike lanes.
Bike lanes are ableist and classist. Only healthy citizens with an excess of time and energy are able to use them for trips. The elderly, children, those with heart conditions, asthma, or many other health conditions, and anyone needing to transport anything heavier than their own body cannot use the lane. In most cities this represents a minority of the population. Creating exclusionary space for bicycles is the opposite of progressive policy and efficient urban design.
Agreed, like looking at the case inside out.
> Bike lanes do not take away the possibility for those less able to use a car, they strictly add options.
But, that is true only if the bike lanes are “free to build and maintain”. Otherwise, the city is allocating money toward bike lanes rather than something OP would argue is “less ableist”.
The “roadway” itself is another fixed resource, I think? So, either the street gets a bike lane or another vehicle lane, but not both because there is only so much space between the two rows of buildings.
Yeah, that gets into the whole "take the space away from cars" thing.
My opinion is that in cities due to the much higher throughput of bike lanes it can also help reduce congestion, but if the bike lanes don't get used, e.g. due to a fractured network with "high-risk" shared road in-between or very unattractive gutter lanes, that doesn't really do anything. My hope is that cities would be aware of that and that it would only be a temporary thing, but the whole point that initiatives of Strong Towns and others like Not Just Bikes make (among others) is that many cities don't seem to have a clue on how to handle transportation, especially mixed-mode.
One particularly egregious example is removing a lane of traffic on the Brooklyn Bridge in favor of bikes. This is in my opinion an oppressive action in favor of the wealthy who live in downtown Manhattan and downtown Brooklyn.
Have you seen how crowded the Manhattan bridge bike path gets, especially at rush hour? I don't deign to assume anyone's socioeconomic background, but it's also very clearly a wide swathe of the NYC population (I somehow doubt the folks on delivery bikes are living in the wealthy areas).
Were the city willing to invest in the project in a sane way, such as making a separate bike path like the one on the Manhattan Bridge or another tier, obviously it would add value. But as it is as a lane removal it's a lazy and badly planned move that snarls the middle class in traffic (which is already regularly backed-up onto the collapsing BQE) to allow the upper class to "enjoy" a "scenic" ride next to a bunch of smog blasting trucks. And maybe help a couple of door dash drivers I guess.
There are over 80,000 delivery cyclists in NYC.
https://inthesetimes.com/article/doordash-delivery-workers-d...
Most people can use an electric bike (this checks the energy part) and with electrical cargo bikes can transport a lot without a lot of physical exertion.
And, last but not least, for those who truly can't use anything bike-like the fan-favorite netherlands allows the use Canta, very small microcars, on bike lanes. These are way cheaper than cars and need less skills to drive, so elderly can drive them as well.
Way better than requiring everyone to drive couple tons worth tens of thousands of dollars after absolving an expensive and time consuming course on how to use them without injuring anybody or worse.
PS. I don't know many children that can drive a lot on roads without a bicycle. That's a very weird example. I don't think many people advocate removing sidewalks in favor of bike lanes.
Also, obviously children are not driving cars. But they still use the road as passengers. It is much less common and mostly not possible to have children too large for a baby seat but too young to travel on their own (4-12 years old or so) using a high traffic bike lane.
They can, but don’t have to. Strange would be the market were bicycles only capable of going at 20mph or 0mph were used.
> We may as well suggest that everyone use electric motorbikes and then car lanes will carry much more traffic.
Good idea!
> It is much less common and mostly not possible to have children too large for a baby seat but too young to travel on their own (4-12 years old or so) using a high traffic bike lane.
There are all sorts of ways around this: e.g. https://www.cyclinguk.org/article/how-transport-children-bik.... And they’re not dangerous when everyone’s on a bike (in a cycle lane): see e.g. Dutch road layouts.
Hmm, maybe it would help if I added an electric motor. But my kids are still at risk of injury if I’m hit by irresponsible cyclist, it will be a horrible tangle of metal and limbs. So maybe we should be in some kind of enclosure…
The physical ability of people is historically specific and if people were to generally cycle most would be able to ‘operat[e] such a contraption’.
It is possible to regulate cycle lanes so that people don’t just zoom around irresponsibly. Curiously you don’t seem to consider equivalent risks from cars (can’t drivers act irresponsibly? is it preferable that they have several orders of magnitude more mass with which to injure people?)
With some physical aptitude you can easily go 25-30km/h on a bog standard Walmart bike. On my unrestricted ebike I never pass 32 on a bike lane (if I'm going faster I just go into a car lane). So an ebike limited at 32 is no more or less dangerous than a normal bike. No need to build a car.
Anyways cyclist on cyclist injuries are much less severe in general than car on car.
Is the injury stat a guess or a fact? I wouldn’t have intuitively been willing to hazard a guess either way myself.
At least where I live (Seattle) if I were to take up biking I'd need a electric assist, since the hills are absolutely massive and steep.
There's also the category of electric bicycles limited to 40 km/h, which are handled pretty much identical to motor scooters (require insurance, cannot use normal bike lanes, unless specified, etc.).
Sure, they might reach more destinations in their car but the humans themselves? They can't reach anything, their mobility was reduced to nothing.
Where do you get this information? Sure they can go faster, but most folks here are decent about things and they sure help going uphill. It means more people can use the bike lanes - notably, people without the strength to go uphill.
an 8 year old is not too young to travel on their own to limited places. If your bike lanes are actually safe, it is safe for them. And realistically, most places let actual children ride on the sidewalk.
Kids too large for a baby seat can generally sit in a pull-behind wagon.
> A majority of the population cannot use bicycles for long trips
well, bicycling _in the city_ is usually meant for short trips, but 95% of my trips are short trips of less than 10km.
> Only healthy citizens with an excess of time and energy are able to use them for trips
excess of time: on my commute i'm on average a lot faster by bike - no gridlock, no search for a parking spot
energy: carbs are cheap
healthy: cycling improves your health and fitness follows an S-curve. even if the ride is arduous in the beginning, it quickly gets easier
> The elderly, children
personal experience (biased): compared to driving, a disproportional amount of cyclists are elderly or children
> those with heart conditions, asthma, or many other health conditions
i don't know about that. a bike courier i know uses an asthma inhaler, but i haven't asked him about it.
> and anyone needing to transport anything heavier than their own body
you're right that there's a limit, but i can impose those same arbitrary limits on cars: "what if i need to transport X which doesn't fit in a car?"
> Creating exclusionary space for bicycles is the opposite of progressive policy and efficient urban design.
it's a safe space for cyclists who are not able or willing to ride on the road shared with drivers. i usually don't mind riding on the road, but as soon as i got my toddler in the trailer i tend to get rather touchy about safe cycling infrastructure.
i'm not sure what you're arguing for though. are you arguing for motorized individual transport, because the disabled, elderly, toddlers prefer cars? or public transport?
Ours is a mid sized town, and we don't need a lot of dedicated bike lanes. For the most part, the cyclists find routes through neighborhood streets where there is minimal car traffic. Cars use the faster trunk roads. The only dedicated bike infrastructure are longer bike paths built on old rail lines, and in some areas where there is just no convenient low speed bike route such as a narrow artery between two lakes. And the long bike paths are at least partially if not primarily intended for recreation.
https://www.whatdotheyknow.com/request/tramlink_tram_priorit...
https://www.andynash.com/nash-publications/Nash2003-ZRH-PTpr...
> A bus lane will carry many more people more efficiently.
i think it's close. yes, you can cram more people on a smaller space in a bus, but the bus - and upping the lines frequency if necessary - is comparably expensive.
the big difference is, of course, personalized transport.
OP is attempting to find an opposition where none exists. Most people are not so wrongheaded, and where you find an advocate for safe cycling, you'll also find an advocate for public transit.
Not everyone can drive: We still have roads. And honestly, I've met a few folks that couldn't drive but could bike if it had 3 wheels (physical limitations) and with the electric bicycles, the folks that cannot do it are becoming less and less. In any case, it is nearly impossible to include everyone in everything: Without this, more people are in harms way OR excluded.
Bicycle lanes are great for powered wheelchairs, and folks can go faster than foot traffic then. You can get such things covered for winter (I see it here in town). So long as you maintain them like you do roads, they can be available all year.
Around here, bicycle lanes are generally alongside foot traffic and have shortcuts. Busses are available, though.
Bike racks are an often overlooked part of having bikes and I wish more places had them! If you cannot keep your bike safe while at work or the grocery store, it doesn't work.
With the installations they have in the US, they're actually less safe to use compared to riding I the center of the rightmost general purpose lane.
The bike infrastructure I've seen in the US has been low or lacking entirely, but I really am never sure how representative it was: I lived in Indiana in small to medium sized cities. In the smaller ones, it really wasn't unsafe to just ride on the road anyway and bike lanes weren't so necessary. At least one city had a walkway/bikeway where railroad tracks used to be and lanes around the river, which made biking decently convenient.
Can you better explain the ableist remark? It sort of comes off like you're being mocking.
Elderly can ride tricycles, often long after they are capable of driving.
Besides that, it gets cars off the road meaning that the disabled/unhealthy population you care so much about will have higher priority access to car infrastructure.
The point of equality is not to force everyone to do the same thing.
Instead, it is to address different people's concerns, differently, so that everyone can get what they want.
Bike travel is about as egalitarian as it gets. You can buy a serviceable bike for a couple hundred dollars, with basically no extra costs - compare that to a car, or even a bus pass, and it’s a screaming deal.
Bike helmets are designed to provide some degree of protection in simple falls, meaning falls that are caused by lots of control as opposed to a collision with another object like a motor vehicle.
I've heard that older Dutch cyclists are dying due to head injuries that could be mitigated by using a helmet or riding a trike insured of a bike.
The other interesting stat is that an hour of bike riding in NL carries approximately the same risk of head injury as an hour in a car in the USA. So, should we make all car passengers wear helmets? It would make them safer…
I can't find any stats of prevalence of various types of injuries in cars, although it does seem to be a thing to get brain injuries in cars (whether that is due to impact or neck/head stopping I don't know)
Truly impressive control - but obviously completely viable when the child outgrows the child carrier on the parent's bicycle.
In that environment, it's no wonder that only more physically fit people will be likely to cycle, because you need some strength and agility to quickly course-correct and avoid danger. But these things aren't inherent to riding a bike. If sidewalks were a painted lane down the middle of the street people with disabilities wouldn't be safe walking on them (just as they are sometimes at risk on crosswalks), but that doesn't mean pedestrian infrastructure is ableist. As someone with a disability that prevents me from driving, I'm glad I have good pedestrian infrastructure in my city, and what passes in the U.S. for great bicycle infrastructure. But I wish I didn't have to share the road with cars.
The problem is that bike lanes are retrofitted on roads that are really not wide enough for another lane. As a result, you get a substandard width bike lane and more narrow general purpose lanes that don't slow down traffic.
This results in close passes and less margin for error.
> if you're really lucky that bike lane will be separated from deadly traffic by a physical barrier
The problem with physical barriers is the fact that they don't continue through intersections. Cyclists are lulled into a false sense of security and don't pay attention to traffic as they approach the intersection. Motorists are likewise not paying attention to cyclists on the barrier separated path. Then both are caught by surprise when their paths cross.
The best option is to just take the lane and follow the rules of the road for drivers of vehicles. You get noticed and you don't have conflicts at intersections. You don't need to be physically fit to do it (other than be physically capable of riding a bike).
Most people won't be comfortable doing this for the simple reason that they'll be going slower than surrounding traffic and it will piss of drivers, which is scary when you're on a bike and they have two tons of metal right beside you. If the safest way to do something is mildly terrifying and generally viewed as antagonistic, we can't be surprised that most people will avoid doing that thing.
I've really been inspired lately by watching the videos on this channel about urban design in the Netherlands: https://youtube.com/c/NotJustBikes
I didn't realize how much urban cycling raises my blood pressure until I watched this video that compares a journey in Canada to a journey in the Netherlands, it's hard to imagine cycling being so safe and easy outside a college campus: https://youtu.be/M8F5hXqS-Ac
People, in general, aren't comfortable engaging in an activity they don't have experience with. A motorist who drives a car for the first time in traffic is not comfortable.
Comfort and confidence come with experience.
> it will piss of drivers
Based on first hand experience riding a bicycle while taking the lane in traffic for more than a decade is that it's a rare occurance. My estimate is that someone shows their frustration maybe once every several years.
On the other hand, riding near the edge or in a substandard width bike lane will result in frequent close passes and frequent close calls with turning traffic (weekly, if not daily).
> which is scary when you're on a bike and they have two tons of metal right beside you
The same rationale could apply to motorcyclists versus motorists in cars, SUVs, and pickup trucks. In fact it can even apply to the latter versus bus drivers, dump trucks and tractor-trailers.
But the way that traffic consisting of vehicles that have different sizes, masses can all share the road is because the drivers follow the same set of rules. It also works for cyclists.
> If the safest way to do something is mildly terrifying and generally viewed as antagonistic
Based on first hand experience, I don't think these assumptions are really valid. If that were the case, then we wouldn't see cyclists on the road at all. But, there are many locations where cyclists ride on the road without bike lanes or separated paths.
> we can't be surprised that most people will avoid doing that thing.
Whether most people will engage in a particular activity should not affect the best practice from a safety and efficiency standpoint. For example, the motorcycle safety foundation focuses on bike handling skills and defensive driving. They're not trying to get more people to use motorcycles for transportation, nor are they trying to get infrastructure built specifically for motorcyclists on existing roads.
Similarly, we should focus on education for cyclists in terms of how to use the existing road network to get to their destinations rather than focus on piecemeal infrastructure that really makes things more dangerous for them by reinforcing bad riding habits that are unsafe.
I'm sorry but what you are saying is simply wrong:
https://en.wikipedia.org/wiki/Canta_(vehicle)
Though I can't say I fully follow TfL's maths on this one.
4 years ago, few bike lanes and very few bikes. Detractors of the newly created ones were arguing about the ressource waste.
Today it is one continuous line at rush hour and some lanes are completely jammed. I am not an expert, but what a change. The pandemic may have helped but it is a true transformation. Many people who would have never bike in Paris a few months ago now bike daily to commute. It certainly took more than just laying lanes, planning and choosing the right places to create lanes has certainly a lot to do with it. But once the main places were connected by safe lanes, it began and never stopped.
Millenia-old super dense city certainly helps too, nonetheless many thought it would be impossible. Would probably be harder in a less crowded place.
First and most recent english article I found about it : https://thewest.com.au/travel/europe/parisian-pedal-power-ng... Not the most precise, but describes well the feeling.
[edit] : typo and spacing
If we didn't believe bike lanes would induce demand for biking we wouldn't say "let's get people out of cars" as one of our major reasons for adding bike lanes. We accept - even hope! - from the start that more bike lanes will cause more biking. It has upsides compared to car commuting.
But because we don't have an already saturated, congested network of bike lanes, we aren't going to be hitting the limits of "why didn't adding more parallel bike lanes reduce the amount of congestion?" - the congestion just doesn't exist, and we'd have to have a LOT more biking to make it exist. And if we get to that point, it's a big win! Fears of future bike traffic should not stop us from building bike lanes.
Everything else about why "they're different" seems like handwaving.
Good bike infrastructure can make or break a commute in speed and safety
In that portion my speed was probably halved, congestion definitely does have an effect at high enough volumes. If more roads in the area had bike lanes this wouldn't have happened and my commute would have been faster (and more pleasant, riding in bicycle commuter traffic is somewhat stressful since everyone wants to go at different speeds). On the other hand if the same number of people were in cars in the same amount of space traffic would definitely have been much slower.
On the flip side, this isn't a city where a large percentage of people commuted by bike. If you turned all the people commuting by car and public transits into cyclists it wouldn't surprise me to find out there were still areas with congestion.
The other issue is that infrastructure doesn't take downgrades into account. So, while it can be safe to get up to speeds exceeding 20 mph (30 km/h) while in the center regular travel lane with a significant space cushion due to it's width, such speeds are hazardous with infrastructure. This means that with rolling terrain, the average speed will decrease significantly because one cannot safely travel at higher speeds on descents to make up for the time lost on ascents.
If you reduce the scale, the speed, the headways, you have greater ability to adjust. While car pileups are expected, bicycle pileups are a thing usually only seen in races when the limits are being pushed. Ordinary bike commuters can navigate safely without rules when given a mixed bike/pedestrian space of sufficient size. Bikes don't get bigger to feel safer. The resulting infrastructure scales better for the cost, and the Red Queen's Race is averted. When bike lanes reach capacity, the failure mode is crowded-stadium, not stand-still freeway. Traffic slows down gradually instead of creating roadside bloodbaths.
Transit does experience more of a headache from induced demand pressure since it also uses large vehicles, and the entire trip experience is contingent on not holding up that one train or bus - while Tokyo's system works, the crowding is notorious, and the train stations have sizable footprints. But as a collective effort, it can also be much more coordinated and deliver useful results from capacity increases.
Here's 60 people in cars, in a bus, on bikes:
https://lh3.ggpht.com/_9F9_RUESS2E/S7tbclwxiPI/AAAAAAAACmw/u...
To quote ru paul... "you're not stuck in traffic. you are traffic."
Those pictures are supposed to bring a point across, not be used for an accurate scientific measurement.
Either way people will be aware not even three out of those 60 cars could drive in the space of that bus.
Still not enough compared to how much space and how many resources they consume, let alone the externalities.
The distance between bumpers actually cancels out (actually it comes out in the car's favor). First notice that in the picture the cars are almost touching, so clearly you mean in fast moving traffic.
In fast moving traffic the carrying capacity of a lane is equal of the inverse reaction time (typically engineers use a large margin of safety and 2 seconds is used -> 1800 cars/(lane hour)).
For bikes, since they travel more slowly, you have to add the time it takes to travel their own length. So the carrying capacity of a lane is 1/(reaction time + length of bike / speed of bike).
The "several car lengths between them" is literally space that exists only because cars have generated themselves by virtue of going very fast (since fast moving vehicles get to where they want to be quicker and therefore get off the road to make space for someone else).
This doesn't mean that cars make sense in dense cities. They don't.
This doesn't means cars don't take more space by virtue of being longer in slow traffic. They do
But it does mean that, if there are "several car lengths between them", they are in fact operating in a more space efficient regime.
Cars do not just take up space driving. They also take up a huge amount of space when not in use.
Where I typically go to it's a relatively minor problem - most places I go to only need 4 to 5 places to park cars.
Work is in the middle of nowhere, again not an issue except that the government employees have reserved the lot by the building for themselves despite it being large enough to house the contractors as well (the govt. employees want to ensure they get the spots nearest the building).
Should the city of Rome have cars? No. But we don't (nor can we!) all live in a small European city
https://www.stadtwerke-muenster.de/blog/verkehr/das-wohl-bek...
If the question is how many people can we shove through a pipe/tunnel/travel network, speed is as much a factor as physical size. Bikes and cars both take up massively more time-space than trains or busses. But pro-buslane voices are rare these days.
If I'm a pedestrian who needs to cross a road, or a driver who wants to turn on to that road, it's equally busy if there's a 10mph cyclist half a block away, or a 100mph car 5 blocks away.
Elsewhere less dense it's probably a different story if you have to travel a few kilometres over a 60 km/h road to reach your destination.
That last part is something which drivers usually leave out in their travel time estimates: off-peak, a car can often go faster to the general area but the time needed to find parking, pay, and walk back usually cancels any savings several times over.
If they are evenly spaced, there will be a car every 0.1 miles - and each car is going 100mph according to this thought experiment. This gives 3.6 seconds to cross between 100 mph cars that probably won't swerve to avoid you and may careen out of control if they do.
Meanwhile, there is a bike every 26.4 feet, and you have 1.8 seconds to cross. 10 MPH is speedy for a bike, but they have to only slightly adjust to avoid hitting you if you make a mistake (and are about 1/5th the width if not less).
I'll take the bikes!
In urban environments, cars have a low average speed (e.g. in London UK it's around 14mph) so I think space will dominate here too.
Also remember that as speed increases, so does spacing for safety reasons.
Cycle infrastructure should be built by taking space from cars, not busses.
https://www.omnicalculator.com/physics/stopping-distance
So if you do the math, bikes take up less time-space, or said better: achieve higher throughput. They are multiple times more dense at their travelling speeds. The only real way out of this would be to travel at unsafe distances.
Also, a bicycle-majority traffic mix wouldn't have to conflict with the presence of high-passenger-capacity buses.
That may be true that cars can have shorter time-distance separation, but I think there's a gap in the modeling there with regard to group travel:
If you have a four-passenger car and compare that to the same group of people traveling together by bicycle, the time-distance separation factor disappears.
Just watch out for freshmen at the first rainstorm. You can tell them apart by their freshman stripe — the result of not having a rear fender.
It's not the cars - they're just tools. It's the insatiable appetite for living space.
There's a trend in the city I grew up in(Warsaw, Poland) that started over 20 years ago and continues to this day - people grew tired of living in crammed, Plattenbau apartments, so they moved to smaller towns(in part inspired by their notion of how Americans live) adjacent to big cities where all the jobs were. Additionally at that time interest rates were so high that this was an option for those who couldn't get a mortgage for an apartment.
Cars followed, but not everywhere. Places close to railways were an exception, but only up to a point, because over time commuters exhausted any spare capacity there was, so the remainder had to drive and bear the not insignificant costs of that. In the meantime a highway was built, but that didn't help for long.
Was Warsaw hollowed-out by this? Hardly. What happened instead is that it started cannibalizing smaller (but still relatively large) cities.
Even with a constant amount of congestion, it means that more people are using the roads which means that having the road is optimizing for people’s choices.
I see that as a good thing, not a bad thing.
I believe that's exactly the point this article is trying to make. Inducing demand for cycling is ideal.
> In 1941, your kid might have walked 15 minutes to the neighborhood school. In 2021, you drive your kid 15 minutes to school. Oh, and this isn't your choice: they tore down the old school and replaced it with a parking lot.
> In 1961, you might have biked or driven a few blocks to a corner store for milk and eggs. In 2021, you drive 3 miles to Kroger for milk and eggs, and there is no corner store. Has your utility increased? Or are you mostly just consuming more resources?
I would argue that utility _has_ increased; It's just that the market has re-organized itself such that the increased utility comes in the form of more flexible locations for houses and businesses rather than in the form of decreased commute times. One grocery store every 5 miles costs far less to maintain than 100 corner stores distributed evenly throughout the city, and you can get more house per dollar buying a house in the suburbs rather than if everyone were competing to buy housing smack-dab in the middle of a city.
I think perhaps a stronger version of the author's argument would be to point out that road use is an externality. Building more efficient roads comes at a significant cost, but road users don't pay that cost in a manner proportional to their use of those roads. Therefore the market does not factor in road construction costs when deciding how to organize cities, only costs of the transportation itself like commute times and gas usage.
I dislike the term "induced demand" for the same reason the author gave. "Induced demand" is really just "demand"; all economic systems work that way. The only thing different about roads is that our current system of road construction funded primarily by income taxes makes road use an externality.
I'm not at all convinced that this is true. It would make sense in a vacuum, but there are a lot of negatives from the road infrastructure necessary for large driving-only grocery stores.
Dense cities have lots of smaller grocery stores rather than a few large ones. I'm sure there's a reason for that.
Hm? In my experience, dense cities have lots of smaller grocery stores, and they also have lots of gargantuan grocery stores.
It does appear to be true that grocery store availability in San Francisco is just a straight downgrade from what you can find in e.g. much of the rest of the Bay Area. But that's a choice by San Francisco, not some truth about cities.
In Berlin there are probably only a handful, and they're not in the city center.
The problem of course being that road construction is _not_ free; we've just created an incentive structure that causes the market to behave as it it were.
The only difference is the appearance that the demand is truly endless. Building roads is a subsidy to cars. People don't pay for the roads they get for free. The optimal strategy becomes driving because public transport is "inconvenient" because the alternative to bad public transport isn't better public transport, it's more cars. So, now the entire city wants to drive. Of course, the problem with that is that cars are such an inefficient means of transport that it's impossible for everyone to drive. The fairy tale of induced demand is born.
And luckily, except for outside Amsterdam Centraal and a couple of other places, it doesn't matter: The fixed and variable parameters of the model are far above where we want to be and far above where we would be, if we reduced single occupancy car-type vehicle use.
If we include the crazy, semi-fatal Dutch microcar, I think we might get to the worst of both worlds: thousands of people old and young driving microcars like they are in Legoland on a toy road, but the road isn't toy.
- Roads/cars often leads to the phenomena of something like grid-lock. A network might be able to throughput 100 cars a minute when only <=100 cars are trying to get through, but try 101 and it starts dropping: If 120 cars attempt passage at once, congestion actually causes the throughput to drop to like 80 (think of those backward-propagating traffic-wave videos). If 150, throughput drops to 70 etc.
- You can add more roads/highways but if it doesn't address certain chokepoints, that throughput will still start descending at some point (though maybe a bit higher now like 110 cars/minute).
- Sometimes you can address the chokepoints, but after some expansion the remaining chokepoints are essentially having the buildings and city intersections themselves, at which point you can only address the bottleneck by rebuilding buildings further apart, which leads to a cycle of worsening pedestrian access, local-depopulation, and more cars.
- And then finally, maybe bikes are different in that they are small and agile with a congestion-failure-mode of being walked. It's hard or unlikely to get to a bike usage level that would lead you to want to move buildings very far apart to support them.
- Or maybe bikes are just simply so small that the preferred distance between buildings anyway (for sun light, privacy) can support most realistic biking numbers (which would be limited by density limits anyways: elevators only practically go so high, commuting biking trips can only be so far).
- Ultimately I wish there as a bit more explained here, maybe by someone that designs traffic/city simulations if that's how the best cost/benefits are tested now. It's really confusing that urban planning advocates concentrate on the un-improving car-trip-time/congestion KPIs like it's a dunk when it really seems some throughput-capacity utility metric would be more important.
I only live in the city I do because with a car payment, it would have cost more for me to live in the suburbs. In the city I can ditch the car.
It applies to things like traffic, and yes, housing.
If building more housing lowered rents, I could finally afford a place in NYC, or LA, or SF. Unfortunately it doesn't work that way. But I wish it did.
And like, sure, on some level that's kind of true and you can argue this but it completely misses the point that giving human beings the things they want - safety, privacy, freedom, mobility - is generally considered a good thing and the lack of it is called poverty.
So cities should want to induce demand in other types of transport (trains, busses, bikes, walking) and try not to induce demand for cars.
Thus, if you wish to decrease your commute as a driver, the best possible strategy is to advocate for increased alternatives.
I’d say induced demand applies to any kind of suitable way of commuting
What I'm seeing in a city with growing bike infrastructure is the increased attractiveness of city homes which are "mid-distance" from jobs i.e. places which are too far to be walkable but within biking distance - if you have to use a car anyway, then you might as well go a bit further and get a suburban home instead, but biking augments public transportation in allowing a bit larger "dense city" instead of a lot larger suburban sprawl.
Will building more lanes “solve” congestion? No! Will building more lanes allow more people to get to more places? Yes!!!
Latency and throughout are two different metrics. Building more road does not necessarily reduce latency. However it does increase throughput. This means more people have more access to economic opportunity; and that’s a good thing.
I rode my bike across the country and my favorite city for cycling is still Cleveland. Not a whole lot of bike lanes, but wide enough roads and flat terrain. And the only time I was ever struck by a vehicle was when I was riding in a bike lane (because they were trying to turn right).
Only 1% of people are brave enough to do this.
For bikes to have a significant mode share, it has to be more comfortable than "just mix in with the high speed SUVs."
Plenty of examples of high mode share, Copenhagen and Amsterdam above 50%, and they do not ask bicyclists to mix with fast dangerous cars.
Cycling showdown, Amsterdam vs. Calgary
https://youtu.be/M8F5hXqS-Ac
Why not? If there’s space for an entire road there’s more than enough for a bike lane or two. With the possible exception of mountain-side single-lane roads where cars barely fit.
US cities need to be built around bikes. There are known models that work (Amsterdam). There just needs to be a significant paradigm shift in American mindsets and dependency on vehicles.
Physical separation is needed for lanes with radically different speeds. Today, sidewalks (4 kmph) are separated from cars (40+ kmph). Because of demand of people traveling around 20 kmph, we need another separated lane for bikes and other e-mobility crowd that is able to move approx. in range of 10-30 kmph. Because of safety new lane must be physically separated.
Also, there should be wise to set some speed limit for these lanes, like 30 kmph, for cases when lane is used by hi-powered e-mobility vehicles.
In theory, parts of town where car speed is so limited to speed of bikes (25 kmph?), separation in many cases disappear. Nobody wanna be driving in such speed anyway.
1) more roads means less space for houses 2) this means people live farther away from where they need to go 3) this means they are more dependent on their cars 4) this means there is inevitably congestion and you need more roads 5) go to 1
A single road can attract travels which begin or end far away from the road. So its effect is felt on a larger territory and further away. A road needs only few exits to be connected to other roads.
Bike lanes are more like capillary network than arteries. A single bike lane is almost useless, because it can serve only travels which begin and end in a narrow strip around the lane (maybe a block away). Two bike lanes which are not connected will be used much less than two connected lanes. Even a single discontinuity of the network can make bike travel unfeasible.
So rather than talking about lanes, we should talk about lane networks and their density. And up until certain density the network won't be used much. Only after reaching that threshold we can talk about effects it may have on city development. Similarly, a car road will not generate induced demand nor attract much traffic if it is missing a bridge across the river.
Let say a bike lane attracts traffic if the starting point and the destination are within w/2 from the lane. Let's assume uniform distribution of potential starting and destination points. Then in a city area A, a bike lane of length L will attract only Lw/A potential commutes (within a strip around the lane). There are two important observations to be made: 1) the induced demand is proportional to the length of the network L, 2) parameter w is probably small, likely ~ 200m, so 1 km of a bike lane will have a smaller and more local effect than 1 km of the road. To cover 1 km² of urban area, the well connected network would have to be a grid with the total density of bike lanes ~ 10 km / km².