Reclaim the streets

Wouldn't it be nice if the city council closed off Princess Victoria Street permanently to traffic, and perhaps roads off it like Waterloo Road, The Mall and Portland Street up round by the Clifton Sausage.
It would be great and would surely attract more people to the area because it would be even nicer than it already is to walk around and shop.
Maybe they could do it at weekends as an experiment.
I've no idea what to do with the traffic and I'm sure it would make it even more of a nightmare to park etc, but you could have proper pavement cafe culture and not have to worry about getting knocked down coming out of Strada or The Quadrant after a glass too many.