I-15 Express Lanes Study. Phase II: Recommendations.

摘要

The primary objective of this research was to recommend actions that will improve average speeds in the Express Lanes (ELs) such that the lanes meet Utah‘s goal of 55 mph. To accomplish this objective it was important to investigate the current usage of both the ELs and the General Purpose (GP) lanes along the Wasatch Front. This involved an evaluation of EL and GP lanes by user type (e.g., single-occupant vehicle (SOV), high-occupancy vehicle (HOV) 2, HOV 3+, ?C? decal, Express Pass user, motorcycle, bus, freight vehicle, and emergency vehicle) to better understand the breakdown of vehicles in the lanes and to calculate average vehicle occupancy (AVO). A second objective was to examine violation data to determine ways to reduce violator rates. The third objective of the research was to recommend ways to control Express Pass traffic and to evaluate changes to toll rates and to estimate the impacts on speed of specific toll increases along the corridor. The final objective of the research was to analyze ?C? decals in the state to evaluate the impacts of increasing the number of ?C? decal permits issued statewide. The data collected were examined to better understand the speed-flow relationship on the ELs and to estimate the impact of volume changes on speeds in the lanes. All of this information allowed the researchers to estimate the impact on EL and GP lane volumes and speeds under a combination of EL education campaigns, increased EL enforcement, increased EL peak period toll rates, and the impact of increasing the ?C? decal cap. Depending on the scenario analyzed, it was determined that the speeds in the ELs could be expected to increase as a result of the recommendations. The extent of the increase is dependent upon the scenario chosen and the response of the traffic to the increases and was projected to range from -4.7 mph (for an increase in ?C? decal vehicles) to a maximum of 7.8 mph for a combination of education, enforcement, and increased tolls