Amazingly, not everyone understands the link between road building and traffic congestion. Well, maybe this isn’t so amazing because the common solution — building bigger highways — is so simple and easy to grasp while the real life consequences are not obvious.

Transportation infrastructure development is in some ways analagous to providing welfare for the poor. There are effective ways of getting the job done, and there are ineffective ways.

First, let’s go over the ineffective ways, which are parochial, one-size-fits-all solutions, like traditional AFDC — the wasteful predecessor to TANF. In its intial years, I’m sure AFDC did quite well in helping to alleviate poverty. After all, the Depression was in full-swing at the time, and just about any government program short of violent coersion would have helped the situation. Similarly, the big highway approach to transportation infrastructure development is a nice idea at first, but its benefits quickly evaporate due to the sort of dependent behavior it encourages.

In 1992, Anthony Downs published his book, Stuck in Traffic, where he describes a phenomenon known as Triple Convergence. When a highway is widened, commuters change their driving patterns in three specific ways:

1. Many drivers who formerly used alternative routes during peak hours switch to the improved expressway (spatial convergence).
2. Many drivers who formerly traveled just before or after the peak hours start traveling during those hours (time convergence).
3. Some commuters who used to take public transportation during peak hours now switch to driving, since it has become faster (modal convergence)

Downs discusses some solutions in his book, including increasing transit funding, raising gas taxes, and increasing housing densities, but not necessarily expanding the transit service area. These are the more effective solutions that not only reduce dependency, but also improve the local quality-of-life standards.

President Bush famously remarked that “America is addicted to oil,” but that is not the whole story. Our real addiction here is to highways and cars. Getting ourselves out of the crack carcaine habit will mean political reform more than it means finding alternative energy sources.

That level of political reform once happened with welfare. Although the TANF solution was not perfect, what we have today is a more effective system than AFDC. It’s possible that the same can happen with our land use and transportation policies.