There’s no reason that cars in urban areas should be capable of traveling more than 20 mph.
Slowing cars with speed limit reductions and enforcement is only part of the solution:
“A ramming attack carried out at 20 mph is not going to cause great harm. A vehicle moving at 20 mph can more easily be evaded, and any impact is much less likely to be fatal.
If we address this vulnerability, not only would intentional vehicular attacks lose their destructive power, but the far, far larger number of traffic fatalities and injuries caused by ordinary negligence and recklessness would also plummet. The potential to prevent this routine violence and the staggering loss of life and limb it generates is the most compelling reason to cap car speeds.”
The other and even more effective is technology that prevents cars from traveling faster than 20mph in cities:
“The transition to 20 mph cars in cities would be far simpler than any hypothetical transition to all-out autonomy, while delivering huge public safety benefits. We can live in cities where cars don’t travel at lethal speeds. In fact, we should insist on it.”