I don't get it. The article clearly outlines the factors accounted in the safety score, and vehicle speed is not one of them (at least not directly). Yet the author and apparently others are intentionally driving slowly to boost their score? That doesn't make sense.

You can definitely "game" the score (to an extent) by making unnecessary trips, i.e. driving to give it more data, but driving abnormally slowly on those trips doesn't help anything. That is, unless you think driving 55 mph will help in the measures, but I'm skeptical of that.

The forward collision measure is based on number of miles, so if you drive 100 miles with no warnings, that's scored the same way if you were driving at 55 mph or 80 mph.

For the others (hard braking, aggressive turning, and unsafe following), each computes the percentage of time you spend doing the unsafe thing relative to doing it safely. If you want to improve those measures, you need to actually spend more time braking, or turning, or following at >50 mph and less than 3 seconds distance. Just driving a slow constant 55 mph on the highway won't change those measures at all, as I understand it.

The forced disengagement measure is just whether or not the car put you into autopilot jail for not paying attention while autopilot was active. I'd hope no one is getting put in that jail, but especially not if they're trying to be on their best behavior.

Anyway, from the Tesla FAQ, I find the 'predicted collisions in 1 million miles' formula fascinating:

    Predicted Collision Frequency (PCF) = 0.682854
      x 1.014495^{Forward Collision Warning per 1,000 Miles}
      x 1.127294^{Hard Braking}
      x 1.019630^{Aggressive Turning}
      x 1.001444^{Unsafe Following Time}
      x 1.317958^{Forced Autopilot Disengagement}

Hard braking and forced autopilot disengagement are, in their model, big predictors of a collision. I'm surprised to see unsafe following at such a low weight.