ASCE Journal of Transportation Engineering 131(6) pp.477-481 Balancing Efficiency and Equity of Ramp Meters

A new freeway ramp control objective – minimizing total weighted travel time is presented in this study. This new objective function is capable of balancing efficiency and equity of ramp meters, while the previous metering objective – minimizing total absolute travel time is purely efficiency-oriented and hence produces a most efficient but least equitable solution. When certain assumptions hold, this metering objective is shown to be equal to minimizing non-linearly weighted ramp delay. A simulation method to achieve the new metering objective is developed and demonstrated using the example of BEEX, a new ramp control strategy also developed in this study, in a microscopic traffic simulator.