Improvement and Simulation of Bottleneck Ramp-Metering Algorithm

The Bottleneck Ramp-metering Algorithm is discribed briefly.Some shortcomings of the algorithm are exposed due to lack of prediction mechanism, including time-lag which leads to governing error,and wide fluctuation of traffic flow when the mainline have traffic jam.Virtually,these shortcomings result from the two limiting conditions of the algrithm,which are too restrictive.This paper tries to soften the conditions to get anExtended Bottleneck Ramp-metering Algorithm.At last,simulation is carried out and control effects are compared between the origin and extended Bottleneck Ramp-metering Algorithm.The simulation results show that the extended algorithm is more robust and can stabilify the traffic flow more quickly and smoothly.