Study finds increased speed limits have cost 33,000 lives.

The Insurance Institute for Highway Safety (IIHS) has released a new study that claims increased speed limits have cost 33,000 lives in the past 20 years.

According to the organization's research, each five mile per hour increase in the maximum speed limit results in a four percent increase in fatalities.  The increase on interstates and freeways is even more dramatic as the IIHS says each five mph increases raise the fatality rate by eight percent on these types of roads.

Speed limits are set by the state but that hasn't always been the case as Congress mandated a National Maximum Speed Limit of 55 mph in 1973.  The decision was made as a result of the oil crisis but lead to a dramatic decrease in fatalities.

Restrictions were eventually relaxed in 1987 and the law was officially repealed in 1995.  Since then, speed limits have been increasing as six states now have 80 mph limits while Texas leads the nation with an 85 mph speed limit.

According to the study's author, IIHS vice president for research and statistical services Charles Farmer, "Although fatality rates fell during the study period, they would have been much lower if not for states' decisions to raise speed limits."

Source: IIHS

Gallery: Higher speed limits lead to more deaths