I've been a supporter of congestion pricing from the day Mayor Bloomberg announced it. In fact, this blog started as a way for me to jot down arguments I found myself making over and over again in favor of the congestion pricing plan and later the Richard Ravitch bridge toll proposal. Since then I've expanded to many other areas of transportation. In particular, I've spent some time making my transportation policy goals more explicit than they were then, and describing the cyclic way that these policy decisions reinforce or undermine themselves. Lately, bridge tolls have come back into the media again, so I wanted to explicitly connect them to my goals.
First, the inherent advantages of encouraging people to shift from cars to transit for suburban-to-center commuting:
Reducing carnage. By discouraging driving, tolls decrease the number of cars on the streets. This does not only include the cordon area, but potentially the entire commute route from home to the zone. It is important to note that this does not by itself reduce carnage, and may in fact increase carnage if the increase in available capacity encourages drivers to go faster.
Reducing pollution. By discouraging driving, tolls decrease the number of cars on the street. By decreasing idling, they reduce the amount of pollution that each car spews.
Increasing efficiency. At a minimum, tolls encourage efficient use of our bridges, and of other car facilities to and in the cordon area. By decreasing demand for the bridges and other car facilities, they may spare us payment for the reconstruction or expansion of these facilities. They also decrease the demand for other driving subsidies, such as oil wars.
Improving society. By encouraging people to take transit from their homes in the suburbs, tolls will encourage denser suburban living, increasing demand for transit-oriented development and thus contributing to a critical mass for walkable suburban downtowns. This will give people alternatives to "bowling alone" and soccer chauffeuring.
Access for all. The increased demands for transit-oriented development will provide better access for the elderly, the young, the poor and the disabled.
Second, some effects that require combinations. If traffic calming measures are introduced, cordon tolls can definitely reduce carnage. If buses are exempted from these traffic calming measures, the buses will go faster, giving them an advantage and increasing farebox recovery. If the toll revenues are allocated to transit, they will allow transit to expand.
The increased demand for transit and decreased demand for driving will also have cyclical effects. It will permit better economies of scale, allowing expansion. It will increase support for government subsidies to transit and reduce support for driving subsidies. If transit has more frequent service and better coverage, it has a better advantage when competing with private car use. It will tend to discourage car use beyond the tolls themselves. These cyclical effects will compound the effects described above.
Those are the advantages of a pure cordon toll system. Some of you will probably see where I'm going with this...