In the Los Angeles Times this weekend, Tim Rutten pointed out why congestion pricing schemes are problematic in parts of the country that don't have an extensive public-transit infrastructure (i.e., the vast majority of it):
Congestion pricing will reduce traffic as well, but it will do so by allocating a precious resource by income. In California, we long have used everybody's tax money--mainly from gasoline purchases--to build and maintain roads.
Moreover, in Southern California, the middle class and working poor have no choice but to use the freeways to get back and forth to work and school because, decade after decade, public officials have encouraged urban sprawl while neglecting public transit. For most commuters today, the highway is the only way.
The reality is that you can't reinvent development patterns overnight, and it's unacceptable to implement congestion pricing on roads paid for through (regressive) gas taxes. If you're going to do congestion pricing there have to be alternative modes of transportation readily available before you make driving during rush hour prohibitively expensive for the working poor. The problem, of course, is that this involves convincing voters to pay for public-transit infrastructure before anyone really uses it, which is politically difficult. In California, anyway, the more likely method of reducing traffic is probably just to push people out of the state thanks to the high cost of living.