The impact of an on-ramp meter on the departure-time distribution onto an urban motorway in Delft that connects a residential area in Delft with the A-13 motorway that links the Northern and Southern parts of the Randstad was investigated. To do this, a simplified version of an existing departure time model that can model the trade-off between travel time and departure time for shifts of up 30 minutes from the desired departure time window is used. The departure time model is an OGEV model, and is based on research carried out by third parties. From the observed on-ramp flows and travel times on the urban motorway, the latent demand profile can be calculated as has been described by previous authors. Once this profile is known, the departure time model can be used to predict the departure time shifts due to the ramp-metering scheme. It is assumed that the ramp-metering scheme will have negligible impact downstream of the ramp meter, but that it may result in travel time benefits for travellers upstream of the ramp meter. Consequently, the main effect of the on-ramp meter on travellers from the residential area in Delft will consist of the delay imposed by the ramp meter. Therefore the delay caused by the on-ramp meter to the A-13 motorway will be the main factor affecting any departure time shift. The road authorities plan to activate the ramp meter on the on-ramp to the A-13 in the course of this year; if this planning can be realised the predictions can be compared to the observed effects. For the covering abstract see ITRD E124693.
Abstract