Does this Environmental Regulation Endanger Safety?

Changing speed limits along a stretch road raises the probability of accidents. The effect might be small, but people slowing down has some risk. In the past there was some academic research showing that accident rates depend on differential speeds, and these changes in speeds would contribute to that problem. Anyway, it would be interesting to measure how big of an impact this might have.

The speed limit for truckers will drop from 70-to-55 miles per hour. The new speed limit for everyone else will be 65 miles per hour.

The reductions will affect more than 22 miles on I-81 and 12-and-a-half miles on I-26, from the Tennessee-Virginia border to the Sullivan-Washington county line.

Local officials requested the change to help bring the county into line with the Environmental Protection Agency's air quality health standard for ozone. . . .