Deaths, Injuries Increase With Higher Speed Limits

July 17 -- THURSDAY, July 16 (HealthDay News) -- Deaths and injuries on America's interstates have increased since the repeal of the federal 55-mile-per-hour speed limit in 1995, a new study finds, and some believe it's time to slow down again.

Researchers tracking fatalities attributed 12,545 deaths and 36,582 injuries in fatal crashes to higher speed limits implemented during the 1995-2005 study period.

"Our study clearly shows that policy can directly result in more deaths as well as reducing deaths on our country's roads," said lead researcher Lee S. Friedman of the division of environmental and occupational health sciences in the School of Public Health at the University of Illinois, Chicago.

Their results show that seemingly harmless policy decisions can have long-term repercussions, the researchers said. They called for implementation of a national speed management policy that would include a maximum speed of 55 mph and development of camera networks to curb speeding.

The report is published in the July 16 online edition of the American Journal of Public Health.

For the study, Friedman's group examined deaths and injuries in fatal car crashes on rural interstate highways, urban interstates and non-interstate roads.

They found a 3.2 percent increase in deaths because of higher speed limits on all types of roads in the United States. The largest increase -- 9.1 percent -- was on rural interstates, followed by urban interstates at 4 percent. "These roads were the main locus of raised speed limits," they noted.

Some states had imposed a 65 mph limit. Others went to 70, and still others, 75. The solution, said Friedman, is to bring back the 55 mph speed limit.

"Reduced speed limits would save lives," Friedman said. "They would also reduce gas consumption, cut emissions of air pollutants, save valuable years of productivity and reduce the societal cost of motor vehicle crashes," he added.

Although many factors contribute to passenger injury during a vehicle crash, the kinetic energy transferred to the occupants is the causal agent of injury, Friedman said.