Incorporating nonuniform arrivals in delay variability modeling at signalized intersections

The delay vehicles experience at signalized intersections is one of the most important indicators for measuring intersection performance. The interpretation of delay variability evolvement at intersections gives a comprehensive insight into arterial traffic operation. Thus, an analytical model is proposed to investigate delay variability at coordinated intersections. Two different flow rates are assumed for both effective red and green periods in cumulative curves, through which the effect of signal coordination is incorporated in delay estimation. Then, an analogy of Markov chain process is used to explore the mechanism of stochastic overflow queue at signalized intersections. Numerical case studies show that with the decrease of arrival proportions during green, the shape of delay distribution in both undersaturation and oversaturation cases shifts faster towards higher values, implying that the coordination effect between paired intersections has a great effect on the delay distribution. As for delay fluctuation range, favorable coordination is demonstrated to be able to weaken the variability of delay estimates especially for undersaturation conditions.