Typically these bans are limited to the inner city or the historic center, there is - outside of some small towns in Switzerland - no major European city that I am aware of that has banned vehicles outright.

The towns that have banned vehicles completely that I am aware of are all small and have simply set up a major parking lot right next to the access road into town. For the ones that I am aware of this was a practical thing to do because the streets in winter were already more or less useless due to the snow and the inclined roads so it was a relatively minor step.

A nice example of such a town:

https://en.wikipedia.org/wiki/Saas-Fee

Pop. < 2000, car free since the 1950's.