New Report Calls DC Traffic And Pollution Estimates Flawed

Recent official air quality and transportation predictions for the metropolitan Washington area are severely flawed, according to a study released today by a coalition of Washington area environmental and civic organizations. The findings indicate the region will continue to fail to meet federal health-based air quality standards. (Copies of the report are available at www.environmentaldefense.org).

The independent audit, conducted by prominent transportation consultant Norm Marshall, Smart Mobility, Inc., finds that the regional Transportation Planning Board (TPB) computer modeling of transportation congestion and regional air quality used faulty data to paint a worse picture of traffic congestion and a rosier picture of air pollution than is truly the case. “The TPB has been cooking the numbers, just like they did when they analyzed the impacts of Disney’s America a few years ago,” said Michael Replogle, transportation director of Environmental Defense and former chair of the TPB’s travel forecasting subcommittee.

According to the report:

—The computer model, and the way that its data have been manipulated, significantly overestimates future traffic growth and congestion, especially on major roads and bridges. This overestimation of future traffic demand can be falsely used to support the need for additional highway capacity.

—The model significantly underestimates expected air pollution from the region’s cars and trucks. Vehicle emissions of smog-producing volatile organic compounds are likely 14% higher than estimated by TPB for 2005.

—The model fails to account for traffic that will be attracted to new roads and fails to reflect how people will shift travel in response to congestion.

—Substantially expanding road and bridge capacity to “solve” congestion problems is an ineffective approach to such problems, as demonstrated by recent research.

“These are not little computer glitches; they are major flaws that mask the region’s failure to stay within legally mandated air pollution limits,” said Lee Epstein, lands program director for the Chesapeake Bay Foundation. “As a result, future air pollution will be worse, more people’s health will be at risk and more nitrogen pollution will fall into the Chesapeake Bay than predicted.” Epstein added that the findings call into question the adequacy of the last air plan submitted by the region to protect the public from health-impairing air pollution.

“The modeling biases the results in favor of more road building and against transit,” said Replogle. “This will lead to more sprawl and even longer driving trips for everyone.”

“Environmental and citizens groups are calling for replacement of the current traffic model, reanalysis of air pollution predictions, and fair evaluation of a smart growth and transit solution to regional congestion,” said Stewart Schwartz, director of the Coalition for Smarter Growth.

The report was issued by Environmental Defense, Coalition for Smarter Growth, Solutions Not Sprawl, Piedmont Environmental Council, Audubon Naturalist Society and the Chesapeake Bay Foundation.