the advatages about making the city centers pedestrian zones is that the numbre of traffic accidents ivolving pedestrians will be lowered nearly to 0% as cars are not allowed in the pedestrian zones . Another good thing is tha the shops will get more costumers  as a result of more people passing infront of the shops . On the other hand the fact that cars cant get in to the city centers makes it difficould for example for people who work in the city centers because they will have to park outside the city center and have to go walking every day to their work place.

I think it is a good idea to some some pedestrian only zones in th city center but it wont be good to make all the city center a pedestrian zone .