Estimating the Impacts of Access Management Techniques: Final Results (0-4221-2)

This research report summarizes the research activities and findings of the 2.5-year research project to investigate the impacts of access management treatments. The first objective of the project was to estimate the impacts of access management techniques through field data collection at selected sites in Texas and to perform simulation of traffic performance. Findings related to travel time and delay from three case studies are provided in this report. Theoretical corridors were also created and analyzed to provide further insight into corridor performance with changes in median type, driveway density, and traffic volume. The researchers identify key considerations for using micro-simulation (VISSIM) for investigating access management treatments. Generally, the research identified a range of differences in travel time (and relatively small changes in speed) when comparing a corridor with a two-way left-turn lane (TWLTL) with the installation of a raised median along the three case study corridors and three theoretical corridors. The reduction in the number of conflict points along the corridors with access management was large (up to 60 percent for the case studies and up to 75 percent for the theoretical corridors). The reduction in conflict points illustrates the potential safety impacts of access management.