Comparing the New Double Contraflow Intersection to Conventional and Alternative Intersections

Abstract

This paper introduced a new intersection design, the double contraflow intersection (DCI), that could help at big, busy suburban sites, and explored how well it would work. The DCI uses contraflow left turn lanes on each approach to minimize the conflicting traffic flows. The DCI has the potential to provide slightly better capacity than the continuous flow intersection (CFI) and median U-turn (MUT), and much better capacity than a comparable conventional intersection, while mitigating some of the known limitations of the CFI and MUT. Our results showed that the DCI was generally superior to the CFI, MUT, and conventional designs in capacity and travel time. The DCI likely looks about as safe as the conventional and CFI designs, and is as good in through progression as the CFI. The DCI looks to be generally behind the MUT in pedestrian service, and behind the CFI in bicyclist service, but not by much in either case. The DCI looks to be generally behind the conventional design, but better than the CFI, in driveway service and right-of-way needed. In sum, the DCI looks like it could have a future in helping relieve traffic congestion at some suburban intersections and deserves attention from researchers and project teams.