Removing the 55 MPH Speed Limit

Testimony to the Texas Natural Resource Conservation Committee

Good afternoon. I am Dr. Kenneth Green, Chief Scientist with the Reason Foundation.

Like everyone else in this room, I like to breath clean air. Having lived with asthma for nearly 30 years, I can attest to the importance of safe, breathable air. And thankfully, Houston’s air quality is getting better every year, and has done so now for over a decade.

But having grown up in a single-parent household of very modest means, I can also attest that choice and flexibility in mobility, and economic strength are equally vital pillars of safety and health.

Fortunately, as we wrote back in November 2000, in a study touted as “The Solution” to Houston’s air quality woes by the Houston Chronicle, there are innovative ways to clean the air that do not require us to sacrifice that choice, flexibility, and economic health. The 55-MPH speed limit imposed on Houston, however, is not one of those ways.

As we concluded then:

“A speed-limit reduction policy, besides being likely to spark social discord, is based on questionable assumptions about the relationship between vehicle acceleration and emissions. While the effect of reducing the speed limit might be a small NOx reduction in certain vehicles, the overall impact of slowing the flow of traffic will keep all vehicles running longer, as more time will be needed to complete a trip. It is not clear that current models of emissions are a function of speed, and the overall impact of speed reductions on the total vehicle fleet of both light and heavy-duty vehicles does not adequately capture the complexity of the speed/emissions tradeoff. Such uncertainty constrains sound policymaking, in that it invites unintended adverse consequences, inefficiently utilizes resources, and endangers the public’s willingness to accept more reasonable emission-control policies. Moreover, lower speed limits on freeways in the Houston-Galveston area will be very difficult to patrol due to the high volumes of traffic. Law enforcement agencies are unlikely to obtain the additional budget funding necessary to this end. Further, the public may be unwilling to allow resources to be transferred from efforts to control serious crime to highway patrol.”

Innovative alternatives to the 55-MPH speed limit abound. To name only one example, converting the existing, deeply flawed vehicle and inspection maintenance system, into a highly targeted, gross-emitter identification system could provide additional air quality benefits while freeing most motorists (who drive clean cars) from the cost and inconvenience of annual smog checks.

I thank you for the opportunity to help ensure that environmental policy provides real benefits while preserving choice, mobility, and economic health for the citizens of the State of Texas.

Kenneth Green, D.Env., is Director of the Environmental Program at Reason Public Policy Institute and an expert reviewer for the Intergovernmental Panel on Climate Change (IPCC)'s most recent report on climate change. Dr. Green has published several peer-reviewed policy studies on climate change for RPPI, including A Plain English Guide to the Science of Climate Change, Climate Change Policy Options and Impacts, Evaluating the Kyoto Approach to Climate Change, and A Baker's Dozen: 13 Questions People Ask About the Science of Climate Change. He received his doctorate in environmental science and engineering from UCLA in 1994.