Vision Zero is based on a simple principle: if cars are driving less than 20mph a pedestrian collision is highly unlikely to be fatal. So they set a speed limi

Vision Zero is based on a simple principle: if cars are driving less than 20mph a pedestrian collision is highly unlikely to be fatal. So they set a speed limit of 20mph on any mixed use street, and create separated pedestrian/cyclist infrastructure for any street with higher speed limits. The latter is super expensive, but it's what you need if you want usually zero fatalities and to go faster than 20mph. Actually zero all the time is impossible, of course. It's possible that a 5mph collision with a frail pedestrian will kill them. So Norway and Sweden sometimes have a fatality. But a goal of "zero pedestrian fatalities most years" is actually feasible for polities with fewer than 10 million citizens.