Proposition 1. Any time you have congestion, it almost certain that market pricing is absent.
Proposition 2. Market pricing will almost always reduce or eliminate congestion.
From today's NY Times:
Congestion pricing — the concept of charging higher fees to consumers for a good or a service at times of heavy use — is well established in businesses like hotels, long-distance phone service and air travel. And while London and Stockholm have successfully enacted plans that levy fees on drivers who want to enter traffic-clogged city streets, the United States has been slow to apply the concept on the roads (see graph above for an example of congestion pricing in California).
By making people take into account the true cost of driving — beyond gasoline, insurance and lease payments — congestion pricing in theory encourages people to car-pool, or to drive at different times of the day, or to take the train or bus.