Travel Time Evaluation of Synchronized and Milwaukee B as New Interchange Designs

Abstract

This research evaluated the traffic performance of two new service interchange designs—the synchronized design which is related to a superstreet intersection and the Milwaukee B design that is related to a parclo B design—as possible substitutes where existing interchanges are failing. The travel time of vehicles was selected as the criteria for operation evaluation. Over 1,000 simulation scenarios modeled the traffic operation of six different interchanges (two new and four existing interchanges) in different conditions of traffic volume, traffic distribution, left/right turning volume ratios, and heavy vehicle percentage. As simulation validation, real travel times at three interchanges were collected using probe vehicle data that compared fairly well to simulation outputs. A two-way analysis of variance (ANOVA) was conducted to examine the differences in mean values of travel time between the interchanges and to investigate the variables that affected the travel time of each design. Overall, the Milwaukee B showed the best performance among all the interchanges. The synchronized interchange looks promising as a substitute for a diamond interchange with dominant through traffic. The synchronized and diverging diamond interchanges showed almost the same results while handling moderate levels of turning volume.