Alternative Analysis of X-Ramp and Diamond Ramp Designs

摘要

As congestion increases on Texas urban freeways during periods of peak traffic demand, State Department of Highways and Public Transportation (SDHPT) highway design engineers are considering different methods of improving freeway operations. One problem encountered includes when and where to use an x-ramp pattern as opposed to the more conventional diamond ramp design for freeway interchanges. The report presents the results of a research study conducted by the Texas Transportation Institute (TTI) using the combined results of a field study, aerial photographic survey, and an extensive simulation analysis to evaluate the operational trade-offs of both ramp designs.