Cycle length selection in corridor timing is often dictated by critical intersections with the highest level of saturation. Along corridors with balanced volumes and favorable link distances, a resonant cycle length is often sought to provide good progression in both directions of travel. This paper discusses the search for a resonant cycle length at a 5-intersection corridor in Fishers, Indiana over a three month period. The software traffic model suggests a reasonable range of cycle lengths from 104 seconds to 124 seconds for the corridor. This cycle length range is consistent with analytical highway capacity manual delay minimization approaches.

A set of eleven cycle lengths from the 104 to 124-second range are tested over 12 weeks, with each iteration using optimized offset values generated by the Link Pivot progression optimization algorithm to maximize the percentage of vehicles arriving on green, and holding all phase splits constant. There was no obvious resonant cycle identified in the cycle length sweep, however the experiment findings indicate vehicles arriving on green decrease and travel times increase as cycle length increases.As a tradeoff, the number of force off phase terminations on the side-street phases decrease as a result of longer cycles indicating a better accommodation of sidestreet demand. Finally, a Seemingly Unrelated Regression (SURE) model was used to analyze the correlation between cycle lengths, percent of vehicles arriving on green, and travel time indicating a negative correlation between higher cycle length and progression performance.


traffic signals, resonant cycle length, performance measure, corridor progression, vehicle arrivals

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