A study of safety impacts of using active traffic management strategies on congested freeways

The main objective of this study is to evaluate the safety impacts of using Active Traffic Management (ATM) strategies on freeways in terms of the driver's behavior and operational impacts. A few test beds were selected to evaluate the impacts of ATM such as speed harmonization, shoulder utilization and ramp metering. Test beds used in this study were at places where an ATM is either proposed or previously implemented, i.e., where data exists for conditions prior to and after implementation of ATM. Data collected from the test beds were used in a simulation model to evaluate the impacts of each ATM strategy on speed, travel time, crash rates, and emission reductions. This study also used Project Evaluation Toolkit (PET) software to conduct detailed cost-benefit analysis of speed harmonization. Outcomes from this study indicated some performance improvement of using ATM strategies on US 90 in San Antonio, Texas and US 59 in Houston, Texas.