Raising speed limit to 70 Mph on Interstate in Indiana found safe

Washington, June 24 : A new study by Purdue University researchers has shown that the probability of fatalities or severe injuries has not increased after the government raised the speed limit from 65 to 70 Mph on Interstate 65 in Indiana.

"These findings are important because the influence of speed limits on roadway safety has been a subject of continuous debate in the state of Indiana and nationwide," Live Science quoted researcher Fred Mannering, a professor of civil engineering at Purdue University, as saying.

The researcher points out that a nationwide study in 2005 had reached similar conclusions.

"The safety of raising the speed limit has been a matter of considerable concern in Indiana since the state raised its speed limits on rural interstates and selected multilane highways on July 1, 2005," Mannering said.

"Everybody expects that when you increase the speed limit, injuries and the severity of injuries are going to increase, but that hasn't happened on the interstate highway system in Indiana," the researcher added.

He further said: "For example, one study found that a speed limit increase from 55 to 65 resulted in roughly a 3 percent increase in the accident rate and a 24 percent increase in the probability of a fatality once an accident occurred."

Mannering continued: "But then other studies have contended that legislation-enabled speed-limit increases have actually saved lives. One study argued that increasing from 55 to 65 saved lives because of shifts in law enforcement resources, the ability of higher speed limit interstates to attract riskier drivers away from inherently more dangerous non-interstate highways and reducing how often drivers speed up and slow down."

He says that certain studies suggest that even speed limits on interstate highways may not increase the probability of severe injuries.

"If going from 65 to 70 doesn't have a significant effect on the severity of accidents, you have to ask yourself, what about 70 to 75?. At what point does it begin to impact safety?" he said.

He, however, added that any future speed-limit increases should be considered on a case-by-base basis.

The study will be detailed in Transportation Research Record.

ANI