A detailed evaluation of ramp metering impacts on driver behaviour

Ramp metering was first installed in Chicago in 1963 and is now widely employed in North America and European countries to alleviate motorway traffic congestion. A detailed investigation was carried out to study the potential impacts of ramp metering on driving behaviour. An instrumented vehicle and 11 video cameras were used to measure detailed driving performance of drivers merging at on ramps and those on motorway carriageways in a ramp metering controlled intersection with and without ramp metering control. The main behavioural parameters used for the study include: speed, headway, acceleration and deceleration, sizes of accepted gap, merge distance, speed at merge, etc. Based on the study, it is believed that ramp metering does result in driving behaviour changes of traffic on the motorway carriageway and on ramp. It improves the merge condition of traffic at the on ramp, but may cause minor reduction of speeds of traffic on motorway carriageway during the metering time.