Its not that its going to be illegal to drive gas fueled vehicles , its about care manufacturers will have to sell most of their vehicles as eclectic .
Up here in Canada where gas is twice the cost of whats in the US, you see loads of all electric or Hybrid vehicles on the road already.
Of course there is still going to be heavy hauling trucks which run on gas/diesel for while yet.
Recently a neighbor just bought a new Chrysler Mini Van that is electric and another neighbor got a new Hyundai electric sedan .
These guys just lowered their car gas bill to nothing, that saving is now going to the financial loan/lease for those vehicles. ......and they aren't polluting the air in the process.