Study Finds Speed Control Law Repeal Costs Lives
The repeal of the federal speed control law in 1995 has resulted in an increase in road fatalities and injuries, according to researchers at the University of Illinois at Chicago School of Public Health.
The research--published in the September issue of the American Journal of Public Health--is a long-term study to evaluate the impact of repealing the National Maximum Speed Law on road fatalities and injuries in fatal crashes between 1995 and 2005.
According to the study, the law, which restricted the maximum speed limit to 55 mph on all interstate roads in the United States, was initiated in 1974 in response to the oil embargo and had an immediate impact.
"During the first year there was a drop of almost 17 percent in fatalities after the speed laws were reduced to 55 miles per hour," said Lee Friedman, assistant research professor of environmental and occupational health sciences at UIC and lead author of the study.
The law was modified in 1987 and allowed states to raise the legal speed limits to 65 mph on some interstates. In 1995, the federally mandated 55 mph speed law was revoked, allowing states to set their own speed laws.
"The primary finding of our study was that over the 10-year period following the repeal of National Maximum Speed Law, there were approximately 12,500 deaths due to the increased speed limits across the U.S.," Friedman said.
The researchers used a mixed-regression model to take into account when the speed limits changed in each state and the different characteristics within and between each state, such as car volume density, population density, variations in fleet sizes, the types of vehicles on the road, vehicle quality (newer vehicles versus older vehicles), as well as driver characteristics.
The primary flaw of previous studies has been that they have only focused on selected states or regions, Friedman said, or they have used a simple analysis to look at before versus after implementation of the law during a very short period of time.
The researchers suggest that policy makers reevaluate national policy on speed and road safety and consider reduced speed limits and improved enforcement with speed camera networks to save lives.
Speed camera programs have been implemented in England, France, and Australia, and have shown immediate reductions in motor vehicle crash fatalities, Friedman said.
"This is a failed policy because it was, in essence, an experiment over 10 years," he said. "People assumed that increasing the speed limit would not have an impact. We've shown that something has happened and it's quite dramatic."
Friedman's co-authors are Donald Hedeker, UIC School of Public Health, and Elihu Richter, Hebrew University, Jerusalem.
An extended interview as MP3 audio file is available here.