Reducing Greenhouse Gas Emissions Without Reducing Mobility

This year’s six-year reauthorization of the federal surface transportation program is likely to have far greater impact on our transportation future than anything since the launch of the Interstate highway program in 1956. Many organizations are calling for fundamental changes in the federal role, and while there is certainly much that is dysfunctional about the current federal program, some of the proposed changes could make things worse, not better. An example is the proposal released on May 15 by Sens. Jay Rockefeller (D-WV) and Frank Lautenberg (D-NJ) of the Senate Commerce Committee. The first item on their list of “Major Goals of the Federal Surface Transportation Policy and Planning Act of 2009” was this: “Reduce national per capita motor vehicle miles traveled [VMT] on an annual basis.” Many of their other goals were either laudable or innocuous, but this one is definitely harmful, as I will explain...When working through this logic chain with data and numbers, it starts falling apart. First, all of transportation (including trucking, airlines, barges, etc.) contributes 27.9 percent of U.S. greenhouse gas emissions, according to the Environmental Protection Agency. Personal vehicles (cars and light trucks) are 61 percent of that; hence, personal vehicles are the source of 17 percent of GHGs, not one-third, as you will often hear. Second, greenhouse gas emissions from vehicles are a function of speed. Stop-and-go driving (as in congestion) produces much greater GHG emissions than steady-speed driving between 30 and 60 miles per hour; above about 60 mph, GHGs increase fairly rapidly. Third, there is no hard data showing that people who live in higher densities drive significantly less than those who live in typical suburbia. Fourth, there is excellent data from the Australian Conservation Foundation showing that among housing types, townhouses have the lowest carbon footprint, single-family suburban houses the second-lowest, and high-rise condo-type dwellings the highest. This logic chain also ignores considerable evidence that traffic congestion increases with urban density—which of course increases GHG emissions...Reason Foundation