An advanced dynamic traffic managemment tool is ramp metering. Metering traffic on-ramps aims to improve traffic conditions on the motorway, having also occasionally an additional objective to solve traffic problems on the surrounding urban road network. Ramp metering has therefore link level effects on the motorway while its effects on the surrounding urban road network are dependant on the circumstances and the purposes of the specific system, and may thus be link as well as network level effects. Ramp metering systems are fully automatic controlling their lights by using a strategy which is based upon flows, speeds and occupancy measured not only on the on-ramp being metered but also on the adjacent also on the adjacent motorway. The algorithm decides on whether to start metering and at which rate the traffic can be admitted to the motorway. This report describes various aspects of ramp metering on the Amsterdam Ring Road. (A)
Abstract