Comparing the Operations of the Freeway-to-Freeway W-Interchange Designs to Other Freeway-to-Freeway Conventional Designs

摘要

Congestion is a problem at many urban interchanges as traffic volumes increase in high growth areas. A new interchange design created by Dr. Joseph Hummer called the W-interchange (WI), seeks to reduce congestion at a reasonable cost. The freeway-to-freeway design looks to reduce the impacts to the freeway vehicles as other vehicles merge and diverge from the freeway. The purpose of this presentation is to compare two different W-interchange designs to more commonly used designs for freeway-to-freeway interchanges, specifically the Full Clover Leaf interchange (FCI) and the Four Level interchange (FLI). The W-interchange design utilizes less right-of-way (ROW) than other freeway-to-freeway interchanges, but has more weaving sections. Both W-interchange designs use four bridges to move traffic, including two bridges to cross the freeways. This presentation seeks to compare total times through the different designs using a microscopic traffic simulation package and quantify impacts to the freeways. The two W-interchange designs showed to have a lower total time through the network and a higher average speed than the two conventional interchanges. Since the W-interchanges performed better than the other two interchanges with respect to total time and average speed, the interchanges need further study to see how they compare overall, including construction and maintenance costs. The W-interchange designs are best for a new facility or interchange, but an existing interchange could be retrofitted if there is sufficient spacing between the upstream and downstream interchanges.