Experts Debate Emissions and Driving

Transportation experts gathered in Washington last week for the Transportation Research Board’s 89th annual meeting. With over 10,000 participants and 600 sessions, it is hard to draw any crosscutting conclusions from the conference. With an eye on climate change, however, the TRB meeting indicated the transportation community is engaged and ready for reform. One of the conference’s hot topics addressed the potential to reduce greenhouse gas (GHG) emissions by limiting vehicle miles traveled (VMT). VMT is one of the four major influences on transportation GHG emissions. The others are vehicles, fuels, and the overall efficiency of our transportation system. We need policies to address all four.

At a session entitled “Vehicle Miles Traveled Reduction Targets: Will This Strategy Get the Desired Results?,” the participants debated the effectiveness of VMT targets on reducing GHG emissions. Reducing driving may have been unimaginable in the previous era of urban sprawl and Eisenhower’s interstate highway system, but a confluence of interests in promoting livability and combating climate change has ushered in a new way of thinking about transportation. The idea of limiting VMT is not without its critics, however. Research is ongoing as to how much VMT can really be reduced, on the precise relationship between VMT and GHG emissions, on the costs and benefits of transportation alternatives, and on the distribution of those costs and benefits geographically and by income class.

Perhaps it was the panelists’ connection to the glory days of transportation in the United States or their own economic analyses, but they were mostly skeptical with respect to the efficacy of using VMT targets to reduce GHG emissions. As one speaker put it, “VMT is about technology versus behavior,” meaning lawmakers would use VMT targets to affect behavior due to a lack of confidence in technology.

Another speaker defined VMT targets and the subsequent effects on land-use policy as a “blunt instrument.” They argued VMT reductions would force a reorientation of the population in the United States without necessarily reducing GHG emissions. Furthermore, one panelist claimed VMT targets would be highly regressive.

The lone advocate for VMT targets acknowledged some of these detractions, but strongly pushed for the policy as a “good starting point” towards greater land-use reform. His research showed an economic benefit (i.e., jobs) from spending less on transportation, since people tend to spend that extra money on more labor-intensive products. He also highlighted polls and recent trends indicating that people want to live closer together. Lastly, the co-benefits of reducing VMT including improved safety and reduced congestion make the policy worthwhile even without considering the environmental benefits.

The panelists agreed on some things – for example, that researchers do not fully understand transportation behavior, and that there are substantial co-benefits of reducing VMT. They also agreed that a VMT tax would be preferable to the current Federal gasoline tax as a means of maintaining the surface transportation system, though they disagreed over its effects on GHG emissions. Enacting that policy, however, is politically challenging.

A proposal by Rep. James Oberstar (D-Minn.) to reform fundamentally the current transportation system stalled in 2009, and the legislative prospects in 2010 are unclear. In the absence of comprehensive reauthorizing legislation, action by the Administration – for example, through the Federal budget and U.S. Department of Transportation (DOT) rulemaking – will be critical, as will state and local innovation. We could begin to see this needed leadership from the Administration in the form of the President’s budget, which is set for release on February 1st. DOT does have some discretion to improve federal transportation programs under its existing legislative authorities, and the President’s budget could include such reforms. The President could also propose more significant changes, but that would require Congressional approval.

Nick Nigro is an Innovative Solutions Fellow