Citation

Berry DS. Transp. Res. Rec. 1987; 1112: 23-28.

Copyright

(Copyright © 1987, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The feasibility of using volume-to-capacity (v/c) ratios to supplement stopped delay for determining levels of service (LOS) at traffic signals when operating at near-capacity conditions is examined.

RESULTS indicate that the supplemental v/c criteria would be applicable in identifying LOS B, C, D, and E for many combinations of signal timing. Timing plans using the shorter cycle lengths and the longer green-to-cycle length (g/C) ratios benefitted the most because use of stopped delay criteria alone for those cases frequently requires that v/c exceed 1.00 in order to attain a delay value associated with LOS B, C, D, and E. Use of delay Equation 9-18 of the 1985 Highway Capacity Manual should be avoided when there is an overflow queue at the beginning of the 15-min analysis period, or when duration of overflow queueing lasts for more than 15 min.

Record URL:
http://onlinepubs.trb.org/Onlinepubs/trr/1987/1112/1112-004.pdf


TRT Terms: Equations; Highway capacity; Level of service; Overflows; Queuing; Stopped time delays; Traffic signal cycle; Traffic signal timing; Traffic volume
Identifier Terms: Highway Capacity Manual
Subject Areas: Highways; Operations and Traffic Management; I71: Traffic Theory;

Language: en

Keywords

ROADS AND STREETS - Intersections; HIGHWAY SIGNS, SIGNALS AND MARKINGS; HIGHWAY TRAFFIC CONTROL - Mathematical Models