Project Details
07/08/14
06/23/16
Federal Highway Administration Office of Safety
sub to Leidos
Researchers
About the research
The purpose of this task was to provide the Federal Highway Administration (FHWA) Roadway Departure Team with technical support to gather the necessary information and develop appropriate outreach materials for a wide range of audiences on curve delineation treatments. The objective was to achieve positive results in decreasing roadway fatalities and reducing the number of injuries due to crashes when vehicles leave their lane of travel on a horizontal curve.
This project is a subcontract with LEIDOS.
Researchers
About the research
A classic Road Diet converts an existing four-lane undivided roadway segment to a three-lane segment consisting of two through lanes and a center two-way left turn lane (TWLTL). A Road Diet improves safety by including a protected left-turn lane for mid-block left-turning motorists, reducing crossing distance for pedestrians, and reducing travel speeds that decrease crash severity. Additionally, the Road Diet provides an opportunity to allocate excess roadway width to other purposes, including bicycle lanes, on-street parking, or transit stops. This Informational Guide includes safety, operational, and quality of life considerations from research and practice, and guides readers through the decision-making process to determine if Road Diets are a good fit for a certain corridor. It also provides design guidance and encourages post-implementation evaluation.