Optimal Cycle Length Estimation Equations Based on Delay Models of HCM2000

Abstract:

The paper presents a set of equations to estimate optimal cycle lengths for signalized intersections based on the delay models of Highway Capacity Manual 2000.Firstly,theoretic methods to calculate the optimal cycle length with minimum delays are proposed.Then optimal cycle lengths for sample intersections representing typical traffic situation scenarios are calculated.Two equations to estimate the optimal cycle length are developed respectively for two phase and multi phase signalized intersections through regression analysis.The new equations overcome the shortcomings of the famous Webster cycle length equation which is not applicable to intersections with high degrees of saturation.

Key words:traffic control; cycle length; intersections; signal timing