ASSIGNING LONG TRIPS

摘要

Long trips are trips which take longer than the modelled time period to complete. The paper uses the example of trips between Chester and Congleton which is about 90 minutes drive time apart. When assigning these trips only that part of the trip which is travelled on the network between 8.00 and 9.00 am should be assigned to the network during the morning peak hour assignment model (8.00 to 9.00 am). This could be source of error which could affect model validation and appraisal. Matrices are usually built from roadside interviews (rsi), using the time at which the trips were interviewed so matrices built using the Congleton rsi cordon between 8.00 to 9.00 which came from Chester would have left some 90 minutes earlier between 6.30 to 7.30. If these were merged with the Chester rsi cordon, they would be merged with those crossing the Chester cordon between 8.00 and 9.00 am. This could be a source of error. This paper analyses the magnitude of these effects using the Cheshire Sub Regional Strategic Model and investigates whether it was worse for large study areas.