Crashes Increase When Speed Limits Dip Far Below Engineering Recommendation

Speed limits set only five miles per hour below engineering recommendations produce a statistically significant decrease in total, fatal and injury crashes, and property-damage-only crashes, according to a group of Penn State researchers.

“If (however) you lower the speed limit by 10, 15, 25 miles per hour, or more, drivers stop paying attention,” said Vikash Gayah, assistant professor of civil engineering. “We found there was an increase in fatal and injury crashes at locations with posted speed limits set 10 miles per hour or more below engineering recommendations.”

Read the full article at Penn State University.