Reducing the number of vehicle miles traveled on the nation’s highways won’t make much of a dent in greenhouse-gas emissions, says transportation guru Wendell Cox. Writing in Environment & Climate News, Cox presents the stark facts:

It is well-known that as congestion increases, so does fuel consumption, due to longer idling periods, such as at signals or in stopped traffic, more acceleration, and more deceleration. Not only does fuel economy drop when average speeds drop, but it drops even further when traffic congestion intensifies.

Yet it is precisely more intense traffic congestion that we can expect if federal laws and policies should force most development into present urban footprints.

Between 2010 and 2030, nearly 70,000,000 residents will be added to U.S. urban areas, an increase of more than 25 percent. This increase would mean the legislation introduced by Reps. [Rush] Holt, [Russ] Carnahan, and [Jay] Inslee would require a one-third reduction in per-capita driving to achieve its overall 16 percent reduction.

That’s not likely — and the attempt to do so would drastically constrain personal freeedom and economic growth in America’s major metropolitan areas.