After leaving NYC I've lived in more than a dozen European cities over the last five years. The one commonality that I've seen is that where ever an area is pedestrianized it just explodes with life. Terraces, shops, children, dogs.

No one wants to be anywhere near a 100km/hr road. It can sometimes be ok to walk next to a 50km/hr road but it's not nice and it's best to avoid it. 30 km/hr you can stroll or sit on a terrace and it's fine. But when it's 20km/hr or just closed everything changes.

When there's no chance your kid is going to get killed by a car, he can just go out and play. Your dog can sit off leash under your table while you eat. You can be absorbed in a conversation and not worry a misstep will result in serious injury or death.

We somehow just accept that the possibility of death or jury is just outside our door. Like live electric wires running down streets. When you take them away, everyone just relaxes a lot more.