Fast on the Freeway Can Lead to Fury on the Side Streets

Washington, DC – Raising speed limits on highways could lead to more crashes on nearby roads, according to new research by the AAA Foundation for Traffic Safety. This “spillover effect” creates unintended safety hazards for local communities that might not be involved in the decision-making process to raise the posted speed limit on a nearby highway. According to NHTSA, speeding is a significant safety concern, contributing to almost one-third of road fatalities in the past 20 years.
AAA Foundation researchers investigated whether changes to posted speed limits on interstate highways could cause drivers to adopt risky speeding behaviors on local streets. The study looked at crash data before and after speed limit increases on interstates in Georgia, Michigan, and Oregon. Hot spot analyses were conducted on roads within a 1-mile radius of interstates. Researchers found many instances where speed-related crashes increased on nearby roads following the interstate speed limit change, suggesting that drivers exiting the highway continued their faster tendencies.









