20’s Plenty For Us
Here’s some graphs to accompany this concept.
In urban areas, reducing the speed limit a bit doesn’t hurt travel times much. When cars go faster, you have to put more space in between cars, so you can’t fit as many cars in any given stretch of roadway. When they’re slower, they can be a bit closer together, so you can fit more in a stretch of roadway, so even if they’re moving at a slower rate, you’re still getting just as many cars through a corridor. Racing at 35 mph just to get to the next red light means you’re average travel times end up being similar to cruising at a more consistent rate at 20mph.
But phrasing things in terms of driver convenience is a little beside the point. The conversation shouldn’t be about infringing on driver convenience or not, it should be about safety. In America at least 30,000 people are killed by car crashes every year, and so many of those deaths could have been prevented if we didn’t allow cars to travel at killing speeds in urban environments.
People tent to think of car crashes as unpreventable, terribly unfortunate accidents. But when we know how well a driver can pay attention to their surroundings at a given speed, and we know the rate of survival an average person has after being struck at a certain speed, are the crashes that occur when we let people drive above that threshold really accidents?
