ALINEA based On ramp Traffic responsive Local metering Strategy for Expressway in Shanghai

Abstract:

An extension of the feedback local ramp metering strategy ALINEA is proposed for Wuyi on ramp in Shanghai urban expressway network by taking ramp queue length and control threshold restriction into consideration.Based on ALINEA parameters study results and data analysis,the ALINEA parameters values are determined.During the ramp metering cycles,the queue length subsection constraint model is proposed for the ramp queue length to avoid exceeding the accepted queue length.The data analysis determines the control threshold parameters and the Wuyi on ramp control threshold table is then formed.So this local metering strategy for urban expressway includes ramp model control threshold,ALINEA algorithm and queue length subsection constraint model.The off line simulation results show the ramp metering strategy helps to overcome the urban expressway mainline downstream congestion and accelerate the mainline speed.