Study on the Saturation Flow Rate and Its Influence Factors at Signalized Intersections in China

The objective of this paper is to report some findings on the saturation flow rates at signalized intersection in China. Based on the surveyed data and codes of traffic planning and design for urban roads, the base conditions are determined and the base saturation flow rate of 1800PC per hour per lane is suggested. The influence of traffic composition, lane width and approach grade on saturation flow rates is studied. The PCE (passenger car equivalents) for passenger car, buses and motorcycles are developed and the adjustment factors for lane width and approach grade are suggested. It is found that lane width and turn radius have significant effect on the capacity of left-turn lane. Using the PLS (partial least-square method) method, an equation was regressed and also the adjustment factors for lane width and turn radius are developed. © 2011 Published by Elsevier Ltd.