Road design, safety and Vision Zero

[SammyOES]

I wonder as well how the higher speed limit may affect highway capacity. Generally speaking the highest throughput per lane is supposed to be at speeds quite a bit lower than this (80kph or so I seem to recall reading?), but I suppose if volumes increase, the speed of traffic would drop down naturally anyway.

I would have assumed that theoretically the higher the speed limit the higher the capacity. And that in practice you’d see increasing the speed limit increase capacity up until some speed that reflects human abilities (but at which point you’d just stay at that capacity figure). I can’t think of why a lower speed limit would have a higher capacity.

In practice I don’t imagine anything would change. I find increased congestion increases the average speed people go (I think people are willing to speed up to match the flow of traffic but much less willing to slow down) up until some point where average speed falls because of general congestion.