Use of Microsimulation to Evaluate Signal-Phasing Schemes at Diverging Diamond Interchanges. Issue 1 (2017)

• Record Type: Journal Article
• Authors: Warchol, Shannon; Chase, Thomas; Cunningham, Christopher
• Is Part Of: Transportation research record. Volume 2620:Issue 1(2017)
• Page Start: 10
• Page End: 19
• Publication Date: 2017
• Subjects: Transportation -- Periodicals; Roads; Transport -- Périodiques; Routes -- Périodiques; Routes -- Conception et construction -- Périodiques; Roads; Transportation; 388.05
• DOI: 10.3141/2620-02
• Languages: English
• ISSNs: 0361-1981

Abstract

Even though diverging diamond interchanges (DDIs) have been the subject of research for more than a decade, the effort to standardize interchange signal timing has developed only recently. A three-factor fully crossed experiment was conducted to investigate the influence of crossover spacing and increased volumes on the performance of DDI phasing schemes. PTV Vistro software and the dynamic bandwidth assessment tool were used to optimize the split, cycle length, and offset of each of the 72 treatments. PTV Vissim software was used to collect microsimulation data. Mean interchange delay and mean stops per vehicle were selected as measures of effectiveness. Pairwise comparisons were used to determine whether an existing preferred phasing scheme could minimize delays or stops under three cases: ( a ) given spacing and increased volume, ( b ) given volume independent of spacing, and ( c ) given spacing independent of increased volume. The data revealed that a two- or three-critical-movement phasing scheme usually resulted in the lowest mean interchange delay and the fewest stops. Overall, the results provide an initial signal timing scheme for practitioners given a crossover spacing, an increased volume, or both. Future work will include exploring low volumes, balanced interchange volumes, and their effects on the four-critical-movement phasing scheme, as well as the effect of closely spaced adjacent intersections.