SERIES OF NEW LOCAL RAMP METERING STRATEGIES

The local ramp metering strategy ALINEA is the only available feedback strategy that is based on powerful and robust automatic control methods. A number of modifications and extensions were proposed to address specific issues and needs not covered by ALINEA. More specifically, the following new local ramp metering strategies are presented: FL-ALINEA is a flow-based strategy, UP-ALINEA is an upstream-occupancy-based version, and UF-ALINEA is an upstream-flow-based strategy. X-ALINEA/Q is a combination of any of the preceding strategies with efficient ramp-queue control to avoid interference with surface street traffic. The new local ramp metering strategies are discussed with respect to their features, their limitations, and their relation to available strategies. Macroscopic simulation investigations demonstrate the capabilities and limitations of the new strategies.