You still need ambulance access everywhere and delivery access almost everywhere. So you need a lot of vehicle infrastructure even though it’s mostly unused, and vehicles must suddenly share the space with pedestrians instead of pedestrians having sidewalks and designated crossings. Pedestrian streets exist in most cities but the problem of making each street a safe place for pedestrians while ambulances and delivery trucks can still access them isn’t a solved problem. A couple of vehicle terrorist attacks in Europe in recent years highlighted this issue.
The common solution found in European cities is to have one street reserved entirely for pedestrians, and to allow delivery access from the two adjacent, parallel streets. But of course this requires a certain amount of infrastructure within the buildings.
Yes, and obviously it only makes it possible to make half the streets pedestrian streets in an area. To make every street in an area pedestrian-only you’d need a different solution. Deliveries can often be handled in early mornings for example.
