You are only considering safety and discounting everything else. The capacity of the road network is absolutely related to speed. Slowing down transportation

You are only considering safety and discounting everything else. The capacity of the road network is absolutely related to speed. Slowing down transportation across the board amounts to slowing the economy, which has it's own health impacts. It's not obvious what the ideal balance is. For certain, 1 fatality about every 100 million miles driven is pretty low, especially compared to the sheer amount of utility we get from all of these cars.