Right, but how much of that would be affected by policies like these? I guarantee you this won’t happen in rural or suburban areas, and even in urban areas, presumably a good portion of that 10% is public transit, taxis, ride share, etc which wouldn’t be affected. Never mind the fact that these policies will only reduce (not eliminate) urbanites driving to work. As ideal as it may be, America isn’t going to completely overhaul its infrastructure to be more European in just a few decades. It will probably move incrementally in that direction, but the bulk of the commuter emissions problem is certainly going to be addressed by making commuter vehicles more efficient (e.g., electric).