Drive project (V 1035) : Christiane : motorway traffic flow monitoring and control deliverable number 7a : isolated ramp-metering : real life study in the Netherlands

It is the aim of the ramp metering part of the DRIVE project to use the existing expertise to identify the applicability of existing approaches. Field trials should lead to insight in the range of conditions over which approaches are viable, the limits of the applicability of isolated control and possibly lead to motorway traffic flow control improvements. In this document the results of a field trial with ALINEA at the Coentunnel in Amsterdam are reported. It discusses the way in which the trial was set up, implemented, tuned, tested and assessed. The ALINEA-strategy is based on occupancy which is measured downstream of the ramp. The RWS-strategy is based on flow upstream and on spead both upstream and downstream from the ramp. The results show to be in favour of the ALINEA-strategy. ALINEA increases the total service of the system, the motorway and the ramp at the Coentunnel. When homogenisation of the traffic flow is important, the greater deviation of speeds with ALINEA is of importance.