The National Highway System Designation Act of 1995 repealed the national maximum speed limit. As a result, many of the states have increased posted speed limits to 105 km/h (65 mph) for select multilane highways. This study evaluates the distribution of the speed and studies the influence of site characteristics, light conditions, and type of vehicle on the field-measured free-flow speed. The suitability of the Highway Capacity Manual multilane highway rules of thumb for free-flow speed to both an 89- and a 105-km/h (55- and 65-mph) posted speed limit condition is also discussed.
All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Mechanical Engineering