Modeling Factors Influencing the Capacity of Motorway Merge Sections Controlled by Ramp Metering

This paper focuses on studying factors which are likely to affect motorway merge capacity when ramp metering controls are in use. A newly developed traffic micro-simulation model has been used for this purpose and the well known ALINEA and Demand-Capacity local ramp metering algorithms were integrated within it. Several parameters such as critical occupancy to trigger the signals, position of ramp traffic signals, position of loop detectors and length of ramp were considered. The effectiveness of ramp metering for a range of traffic flow conditions has been tested for various scenarios to show the range of values where ramp metering is beneficial.