This paper describes the planning, conduct and evaluation of a series of experiments with freeway ramp control undertaken for the purpose of improving network operations. The development of the control plan included the identification of the critical section, determination of the period of time and degree of control, estimation of the redistribution of traffic, and re-evaluation of system operations. A comprehensive set of measurements was obtained for the network, including expressway and major arterials, for three weeks without control and for three weeks with freeway ramp control. The ramp control consisted of partially closing one on-ramp and metering traffic at a second on-ramp. The effect on the network of the freeway ramp control was evaluated on the basis of vehicle- minutes and vehicle-miles of travel for each link, route, and for the total network. The results indicate that travel time on a network basis was reduced by freeway ramp control.
Abstract