An official website of the United States government.
Here's how you know
The .gov means it's official.
Federal government websites always use a .gov or .mil domain. Before sharing sensitive information online, make sure you’re on a .gov or .mil site by inspecting your browser's address (or "location") bar.
This site is also protected by an SSL (Secure Sockets Layer) certificate that's been signed by the U.S. government. The https:// means all transmitted data is encrypted — in other words, any information or browsing history that you provide is transmitted securely.
Speeding is a significant safety concern and has contributed to almost one-third of road fatalities in the past 20 years. This research investigated whether changing to higher posted speed limits on Interstates can cause spillover effects, or a systemic propagation of speeding behaviors that results in more crashes at nearby road segments. Findings presented in […]