01366377

Component

Double Crossover Diamond Interchange (DCDI) is a relatively new interchange design that has the potential to replace the Conventional Diamond Interchange (CDI). The few DCDIs in operation in the U.S. were constructed in locations without a frontage road and limited research so far has similarly focused on interchanges without a frontage road. This research proposed a three-phase signal sequence and tested the operational performance of a DCDI, at a freeway interchange with frontage roads, under a variety of traffic demand scenarios. The operational performance of the DCDI was compared with that of a CDI. SYNCHRO was used to optimize the signal timing plans, calculate the intersection delay, intersection level of service and the delay of through movements on the frontage roads. VISSIM was then used to evaluate the total network travel time, total network delay, total number of stops and average travel times of selected movements across the interchange (two intersections). Compared to the CDI, the DCDI was found to have shorter or equal cycle length, lower average intersection delay, improved intersection level of service, lower total network travel time, lower total network delay and fewer stops. The DCDI was particularly efficient in reducing the delay for the left-turn movements, especially when the left-turn volume was high. On the other hand, the CDI has the advantage of lower delay for the through movements on frontage roads. This research has demonstrated the feasibility and advantages of implementing DCDI at freeway interchanges with frontage roads.

This paper was sponsored by TRB committee AHB25 Traffic Signal Systems

01362476

12-0045

English

20p

2012

Transportation Research Board 91st Annual Meeting

Digital/other

References; Tables

Diamond interchanges; Frontage roads; Left turns; Traffic delays; Traffic signal phases

Highways; Operations and Traffic Management; I73: Traffic Control

Transportation Research Board Annual Meeting 2012 Paper #12-0045

TRIS, TRB

Feb 8 2012 4:52PM