Cities won’t like that as it discourages business, i.e. how they get their money.
London was one of the first cities to come up with this idea under its former mayor, "Red" Ken Livingston.
It's not an altogether bad idea in some urban areas. Some densely populated cities can reach a point where streets downtown completely shut down. User fees, in of themselves, are not a socialist idea- there is a place for them in situations where certain common resources (such as roads) are limited.
I grew up in a town that made it practically impossible to find parking in the downtown area. Evetually...over a twenty year period...real business moved out of downtown, to the burb’s. There isn’t a single thriving business in the downtown area today...except a couple of bars...banks....and second-hand shops.
In the case of the British towns...it is rapidly teaching folks to shop and frequent places outside of town. It will eventually trigger an event where the inner city is most for tourist only....and then the city will be in serious jeopardy.
My humble opinion of the Obama team looking at something like this...let the cities fix their own problems and don’t get the federal government in the business of car routes.
I read on FR quite a while ago that SanFran and NYC were already considering this. I think SanFran was even testing the idea but I have not heard anything about it since