Scientist testifies against 55 mph speed limit

Published August 1, 2002

Dr. Kenneth Green, chief scientist for the Los Angeles-based Reason Foundation, testified on June 5 before the Texas Natural Resource Conservation Committee regarding the state’s mandatory 55-mile-per-hour speed limit. Following Green’s advice, the committee decided to withdraw the limit on automobiles, which had been written into the Texas State Implementation Plan in 2000.

The Reason Foundation first argued against implementation of the 55 mph limit in a November 2000 study, “Clearing the Air in Houston.” The study’s authors, Green and Lisa Skumatz, warned the speed limit proposal had many failings. Although the city’s leading newspaper, the Houston Chronicle, agreed, the limit was nevertheless put into place. It has been deeply unpopular with the city’s motorists, legislators, commentators, and law enforcement officials.

According to Green, the 55 mph limit was already on the rocks simply due to its unpopularity. A new study of its environmental impacts sealed its fate, showing early reports overstated by 100 percent the air pollution-reducing power of the 55 mph limit. Even those pollution reductions came from the slowing of heavy-duty vehicles rather than automobiles.

With air pollution such a high-profile issue in Texas, and with the implementation of new air quality standards regulating ozone and particulates on the way, the TNRCC’s rejection of the 55 mph speed limit is a positive development.

The federal Environmental Protection Agency has yet to weigh-in on the TNRCC’s decision. Under the Clean Air Act, EPA has the authority to overrule state regulators on such matters as how best to clean the air. The agency’s recent pronouncements about favoring innovative, market-based environmental policy will be tested.