I would take it one step further and say there should probably be small (single lane) roads that run through the neighborhood or an underground carpark with a few freight elevators that run directly into the buildings. Why? For a same reason you mentioned that they should allow cars. If you get a new fridge, imagine trying to walk that sucker from the street to your apartment. You probably wouldn’t need very many freight elevators or access roads to significantly decrease the amount of effort required to get bulky and/or heavy objects to your apartment while still maintaining the general feel and spirit of a car-less community.