Queue Management Techniques for Metered Freeway On-Ramps

Ramp metering is beneficial for freeway throughput, but the ramp queues that are created should be prevented from extending to adjacent street junctions. A recently proposed ramp queue controller is investigated in conjunction with the local ramp-metering algorithm ALINEA. Microscopic simulation is used to compare the queue controller with a popular queue override scheme that is based on specifically designed scenarios and evaluation criteria. It is found that the queue controller outperforms the queue override and leads to fewer instances of ramp queue spillover. The concept is also demonstrated to work properly in an operational field environment.