I recall walking down a new road in the middle of condos on the way to the Western Wall in J'lem. Like all the other cheap construction in the city, the buildings were stone (wood is found in the five-stars) and the road zig-zagged on its way. "Good way to prevent enfilade," I joked with my hosts, and they replied seriously: "exactly".
Some of the best city street views can be had wherever the grid changes orientations. As you approach, broadsides of buildings come peeking out around the corner.
If I understand correctly, Toronto, Sydney, Melbourne, Mexico City, Tehran and St Louis have a majority streets running slightly askew from due North - South or due East - West. Any ideas why that may be the case?
Could be a variety of reasons. Maybe they point to geographic north instead of magnetic north, or it could be just simple measurement error when the city was constructed, or a natural feature of the terrain, similar to the Manhattan and Detroit graphs
Another tidbit about Melbourne (I'm a fan): while most of greater Melbourne orients ~8 degrees clockwise of true north, the Hoddle Grid right in the middle and South Melbourne instead orient ~20 degrees counterclockwise of true north, in order to align with the adjacent stretch of the Yarra River.
Naturally, as a lifelong resident, I lean 8 degrees to the right when reading any map.
It would be interesting to see these diagrams folded in half and into quarters. Which cities have the greatest fourfold symmetry breaking? Which cities have more streets running north than south? (the only case I can think of would be many small one-way streets in a cardinal direction, and one big counterflowing one-way street)
Looking at downtown Charlotte in Google Maps, I see the typical grid pattern of other US cities, just tilted by 45 degrees.
The suburbs follow a similar pattern, but appear to be at slightly different angles. I'm not sure if this would explain the even distribution of road orientations.
Huh? Having a bunch of roads at random angles explains the "even distribution of road orientations", by definition. How would it not?
That's my point. The city is fragmented into tiny grids oriented at random angles. Wherever these grids meet, there are odd intersections and traffic patterns that are difficult to optimize.
Slightly related: I'm on a trip visiting many maya ruins, and I find it fascinating that they were really good at astronomy, their buildings are off by around 1 degree. Tectonic plates moved? What am I missing?!
Are you referring to something on this page or data from elsewhere? The only one close is Mexico City, which wasn't Mayan, but Aztec (and others before that). It was originally an island, so maybe that had something do with the original orientation.
No, I wasn't, so risking all the down votes for being off-topic.
Just in general, I had this observation by looking at (openstreet)maps.
A nice inclusion in this list would be though the planned, checker board colonial towns (like Antigua, Cuenca, or Alejuela), which are surprisingly also off by some degrees, and probably all have their explanation (nearby volcano, river, etc)
Most of the major Maya sites (e.g. Palenque, chich'en itza) have fairly well supported astronomical alignments, usually with the sun around equinoxes and solstices. It's usually at the level of individual buildings though, as the roads are rarely very straight except near the major ceremonial complexes.
The article claims that Seattle is strictly North/South/East/West, which is incorrect. The downtown area (the oldest part of town) has 3 different grids, one is NSEW, and the other two are at angles near 45 degrees.
I don't know how much of the other claims of this article can be trusted.
I would guess its based on the number of named streets. To the north and south of downtown you've got hundreds and hundreds of tiny streets all NESW, and not that many in downtown that are "off" the cardinal.
This is basically it, and Chicago is the same: If you click on the image and zoom in, these diagonal streets are represented, their spokes are just so small you can't see them on the zoomed-out version on the page.
I looked at Warsaw and it also looks off. The "main" grid in Warsaw is the tilted one, which the article shows as secondary. There are very few streets in Warsaw that are pure N/S and E/W.
I guess this might be an artifact due to some missing data?
These things are all about intersections and the intersections they connect with. The angled portions of Seattle's downtown just doesn't have anywhere near the number of intersections as the NSEW part of the whole city.
[1] > it calculates the compass bearing from each directed edge’s origin node u to its destination node v. Now we can visualize these bearings, binned together as a histogram to get a sense of the relative frequency of the streets’ spatial orientations.
It would be really cool if there was an interactive version of these visuals [0] that show the histograms next to the street maps. You could hover over an arc on the histogram and it would highlight the corresponding streets, and vice verse. It could be a fun way to explore how the grid angles vary by area within each city, like lower vs upper Manhattan.
I'm probably not going to get around to doing it myself but maybe someone else might get inspired...
A random bit of trivia about Portland (and it probably explains a lot of the off-axis streets in other cities) is that there was a section laid out to align to true north, and another section of town that aligns with magnetic north. Eventually, those parts merged so now there's some weird pizza-slice shaped blocks (near Powell's, for instance).
Magnetic north changes over time, so effectively our city streets become an effectively permanent record of the Earth's magnetic field at a specific moment in time, not all that unlike the rocks that store the magnetic alignment when lava cooled and we use to correlate seafloor spreading with magnetic field reversals.
This might sound like a dumb question, but I always thought that the streets south of Burnside were aligned with the Willamette River? I love learning about any history/geography stuff, so your comment is super interesting. I grew up outside of Portland, but have only been back a handful of times in the last decade and a half.
As an aside, I wonder how these sorts of road layouts affects people who grow up there in terms of spatial awareness.
The article and linked paper talks about "legible cities" and people struggling to navigate a non-legible city because they don't know which way they are facing if there is not a grid.
Do people who grew up in a rigid grid system have a different way of viewing the world compared to those who are used to more chaotic and organic layouts? If folks don't know where they are going or which way they are facing without relying on the roads being a grid, what other aspects of their lives are impacted by under-developed spatial reasoning?
That's a really interesting question! The two cities with which I am most familiar are San Francisco and London, and (though I'd never thought about it before) my navigational concepts of them are very different.
Getting around San Francisco is, uh, grid-like: I think in terms of "corner of X and Y", and then the relationship between myself and my destination on a coordinate plane. Getting there becomes a series of maneuvers - some of them indirect, for route-efficiency reasons (like, this street has timed lights, or this one permits left turns) - which carry with them very few (street-level, at least) visual images of the route.
London is all about pathways, a choice between more and less direct connections between my location and where I'm going. Just about every landmark and decision-point triggers a visual memory of that specific location and choice.
In San Francisco I can point fairly confidently towards a given destination, drive that direction, and find it by "feel" - eg, by intersecting one of the two cross streets on the coordinate plane. In London, I couldn't do that on a more granular than borough / neighborhood level - like, I'd know how to get to, say, Camberwell from a given location, but not in precisely which cardinal direction it lies, and once I get there I'd need to rely on landmark-based directions (or nowadays, GPS).
Navigation in London is more complex, I suppose (San Francisco has its quirks!), but the conceptual framework it requires leaves me with a more detailed and enjoyable sense of the city itself.
That's one person's experience. I'd be curious to know the extent to which it generalizes.
My mental model of London is basically the Tube map - when I look at a map of where the Tube lines and stations are physically located I find it quite disturbing.
Same here! I only developed a feel for the actual geography once we had a car.
I love driving in London. It demands complete attention, like an action-oriented video game, and the culture (if you will) of drivers is a wonderful blend of courtesy and aggression. Like, if you sit waiting to make a turn onto a busy street you'll never find a gap, but if you assert yourself into traffic someone will always let you in; or, if you and someone else simultaneously arrive at opposite ends of a street with only one traffic lane you're immediately in a race with them to get to the pullout to let the other one by. It's great fun, and made everywhere else I've driven feel like easy-mode.
I'm a North American living part time in Seoul and I get lost using and cycling in small streets all the time, they turn and take random directions and my internal compass doesn't realize I'm now facing East when I thought I was walking North. I prefer cycling on smaller side streets but it's way harder to "guess" my way around detours unless I'm using a map app. I've seen delivery drivers do the same on their scooters, so I guess they feel the same unless they're very comfortable with a specific block. As in, they don't try to guess detours using some mental model of street layout: they check the map.
Also I've learned people don't give directions using cardinal directions: there's no such thing as "walk North on Seorae-ro" (or at least I was told). Which I guess makes sense since the streets on which this would be a useful mean of communicating directions are very few.
I have lived in non-grid cities all my life, but my mental map always approximates things as a grid. I occasionally then get really confused because there’s a square with five sides, or three, because roads aren’t straight or perpendicular in reality. It also affects my perception of distance because I assume parallel roads in a quadrilateral are the same length, but they’re not.
The only exception is the city I went to uni in - when I moved, I bought a map and studied it quite a lot. It’s a city I have a much stronger perception of north in, and I don’t really have the angles problem above, but I still have the distance problem.
Oh man Boston Common always used to do this to me — my brain insisted it is a square when it’s actually a pentagon. It also doesn’t help that Tremont curves from nearly parallel with Beacon by Park St to almost perpendicular by Boylston.
The net effect was that my brain considered the Theatre District to exist in another — largely inaccessible — dimension.
You might find Amsterdam an interesting challenge then. Within the centre area (roughly speaking, the bit enclosed by the Singelgracht), it was planned, but they had in mind (paraphrasing) "the practicality of a grid, but the beauty of curved streets", and so there's a horse-shoe type arrangement overall and then a grid within that.
The effect is that you can walk along a canal, not really notice the curving of it, and be surprised that you're facing 90° or more away from where you expected.
I grew up in an area with a grid, and NSEW comes easily. OTOH I never cease to be appalled by people who are absolutely clueless about which direction North is. How is it possible to navigate ? Do you need a mapping app fused into your brain ?
I've lived mostly in non-grid or barely-grid cities and towns. My youth was spent next to a forest.
The closest thing to grid around here is southern Helsinki, and it's also my least favorite area to navigate in. I'm always off by a block or two, and it feels like it's all the same, no landmarks or character or sense of scale.
But when I'm just a few km to the north, with diagonal streets etc, I can locate myself much easier.
Just a little info, whenever youre in a Dutch city, the house numbers are numbered from the center. So you wanna go to the center of the city, you can use the numbers as orientation.
I wish there was option on maps programs to set default tilt, I live in one of the cities with strong axial orientation and it's annoying maps is always slightly rotated.
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[ 7.7 ms ] story [ 224 ms ] threadhttps://geoffboeing.com/2019/09/urban-street-network-orienta...
> Most of Melbourne’s grid was laid out according to magnetic north, not true north, hence the ~8 degree rotation.
https://en.wikipedia.org/wiki/Lake_Ontario#/media/File:ISS-3...
[1] https://en.wikipedia.org/wiki/Tenochtitlan#/media/File:Paint...)
Naturally, as a lifelong resident, I lean 8 degrees to the right when reading any map.
Though I am surprised to see that Charlotte is such a well-rounded player here.
The suburbs follow a similar pattern, but appear to be at slightly different angles. I'm not sure if this would explain the even distribution of road orientations.
That's my point. The city is fragmented into tiny grids oriented at random angles. Wherever these grids meet, there are odd intersections and traffic patterns that are difficult to optimize.
Just in general, I had this observation by looking at (openstreet)maps.
A nice inclusion in this list would be though the planned, checker board colonial towns (like Antigua, Cuenca, or Alejuela), which are surprisingly also off by some degrees, and probably all have their explanation (nearby volcano, river, etc)
Maybe this statement needs to be clarified a little ...
"Off by one degree" with respect to what?
* the modern rotational polar north
* the modern GPS north
* the modern sunset | sunrise on { longest | shortest } day of year
Or any of these back calculated to the time of the city in questions founding?
It's not clear what it is you think these cities should be aligned to, and are deviating from.
I don't know how much of the other claims of this article can be trusted.
I guess this might be an artifact due to some missing data?
[1] > it calculates the compass bearing from each directed edge’s origin node u to its destination node v. Now we can visualize these bearings, binned together as a histogram to get a sense of the relative frequency of the streets’ spatial orientations.
[1] https://geoffboeing.com/2018/02/street-network-orientation/
I'm probably not going to get around to doing it myself but maybe someone else might get inspired...
0: https://i0.wp.com/geoffboeing.com/wp-content/uploads/2019/09...
Magnetic north changes over time, so effectively our city streets become an effectively permanent record of the Earth's magnetic field at a specific moment in time, not all that unlike the rocks that store the magnetic alignment when lava cooled and we use to correlate seafloor spreading with magnetic field reversals.
The article and linked paper talks about "legible cities" and people struggling to navigate a non-legible city because they don't know which way they are facing if there is not a grid.
Do people who grew up in a rigid grid system have a different way of viewing the world compared to those who are used to more chaotic and organic layouts? If folks don't know where they are going or which way they are facing without relying on the roads being a grid, what other aspects of their lives are impacted by under-developed spatial reasoning?
Getting around San Francisco is, uh, grid-like: I think in terms of "corner of X and Y", and then the relationship between myself and my destination on a coordinate plane. Getting there becomes a series of maneuvers - some of them indirect, for route-efficiency reasons (like, this street has timed lights, or this one permits left turns) - which carry with them very few (street-level, at least) visual images of the route.
London is all about pathways, a choice between more and less direct connections between my location and where I'm going. Just about every landmark and decision-point triggers a visual memory of that specific location and choice.
In San Francisco I can point fairly confidently towards a given destination, drive that direction, and find it by "feel" - eg, by intersecting one of the two cross streets on the coordinate plane. In London, I couldn't do that on a more granular than borough / neighborhood level - like, I'd know how to get to, say, Camberwell from a given location, but not in precisely which cardinal direction it lies, and once I get there I'd need to rely on landmark-based directions (or nowadays, GPS).
Navigation in London is more complex, I suppose (San Francisco has its quirks!), but the conceptual framework it requires leaves me with a more detailed and enjoyable sense of the city itself.
That's one person's experience. I'd be curious to know the extent to which it generalizes.
I love driving in London. It demands complete attention, like an action-oriented video game, and the culture (if you will) of drivers is a wonderful blend of courtesy and aggression. Like, if you sit waiting to make a turn onto a busy street you'll never find a gap, but if you assert yourself into traffic someone will always let you in; or, if you and someone else simultaneously arrive at opposite ends of a street with only one traffic lane you're immediately in a race with them to get to the pullout to let the other one by. It's great fun, and made everywhere else I've driven feel like easy-mode.
Also I've learned people don't give directions using cardinal directions: there's no such thing as "walk North on Seorae-ro" (or at least I was told). Which I guess makes sense since the streets on which this would be a useful mean of communicating directions are very few.
The only exception is the city I went to uni in - when I moved, I bought a map and studied it quite a lot. It’s a city I have a much stronger perception of north in, and I don’t really have the angles problem above, but I still have the distance problem.
The net effect was that my brain considered the Theatre District to exist in another — largely inaccessible — dimension.
The effect is that you can walk along a canal, not really notice the curving of it, and be surprised that you're facing 90° or more away from where you expected.
The closest thing to grid around here is southern Helsinki, and it's also my least favorite area to navigate in. I'm always off by a block or two, and it feels like it's all the same, no landmarks or character or sense of scale.
But when I'm just a few km to the north, with diagonal streets etc, I can locate myself much easier.