As the Speed Limit Goes Up, So Do the Costs
From Texas to Idaho, the speed limit on many rural roads and highways has jumped from 55 or 65 mph to 80 or 85 mph. Aarian Marshall reports in Wired that the increase in speed has led to consequences that can be measured monetarily or in lives lost.
A 2009 study published in the American Journal of Public Health estimates speed limit increases were responsible for 12,545 deaths and 36,583 injuries between 1995 and 2005. The number of rural interstate fatalities we can blame on higher speed limits jumped 9.1 percent during that time.
Faster driving means maintenance costs go up, too. In 2014, researchers working with Michigan’s DOT found that upping rural interstate speed limits from 70 to 80 mph would save 15.4 million passenger vehicle hours a year, but would also cost $163.88 million annually for the design’s estimated 25-year lifespan.
Marshall looks at the reasoning behind the support for higher speeds given the well documented costs. Some of the factors are cultural, others have to do with the politics of Western states, and then there's the great distances between places in rural America.