Fatality rate tied to speed limits
WASHINGTON -- States that raised their speed limits to 70 miles per hour or higher saw a dramatic increase in the number of people killed in traffic accidents, according to a report released yesterday by an auto safety group funded by insurers.
The study, compiled by the Insurance Institute for Highway Safety and based on data collected by the Land Transport Safety Authority of New Zealand, determined 1,880 more people died between 1996 and 1999 in the 22 states with higher speed limits.
A separate review of six states by the institute found drivers traveling the fastest they have since long before Congress repealed the 55-mile-per-hour national speed limit in November 1995. In Colorado, which has a speed limit of 75 miles per hour, researchers observed one in four drivers going above 80 miles per hour.
The 10 states that raised limits to 75 miles per hour -- all in the Midwest and West -- experienced 38 percent more deaths per million miles driven than states with 65-mile-per-hour limits, or approximately 780 more deaths. The 12 states that raised their limits to 70 miles per hour saw a 35 percent increase, or 1,100 additional deaths.
Geographical differences in states may have contributed to the numbers. For example, the report said, drivers may go faster in Western states, where cities are farther apart.
The report didn't examine the effects of other trends, such as the increasing number of sport utility vehicles on the road then.
The Insurance Institute said there is no doubt, however, that when speed limits increase so do deaths. When the national speed limit of 55 miles per hour was adopted in 1974, fatality rates dropped, the Insurance Institute's chief scientist Allan Williams said.
The Insurance Institute's separate study of speeds in Georgia, Massachusetts, Maryland, New Mexico, Colorado, and California also found that when rates are raised on rural interstates, speeding increased on urban interstates.
Average travel speeds on urban interstates in Atlanta, Boston, and Washington were the same as or higher than on rural interstates near those cities, even though the speed limits on those urban interstates were 55 miles per hour. In Atlanta, 78 percent of drivers on one urban interstate exceeded 70 miles per hour, the report found.
