This study quantitatively evaluates effects of trip reservation systems that manage motorway traffic demand on holidays based on a stated-preference survey. Traffic congestion analyzed in this study occurred at a bottleneck on an inbound inter-city motorway in the Tokyo Metropolitan area from 6:30 to 14:20 on a holiday in 1994. It was about twenty-one kilo-meters in the maximum length, and was estimated about forty-five minutes in the maximum travel time. In other words, the travel time was three times that of vehicles passing through the section at a speed of one hundred kilometers per hour. In this case, it is estimated that less than fifteen minute adjustment of the departure time of each traveler could level the traffic demand so that it would not exceed the bottleneck capacity. There is an idea of trip reservation systems that adjust departure times of travelers on motorways in a similar way to train seat reservations. The revenue and expenditure of the system can be balanced by discounts on tolls for those who change their departure times and extras for others. The preference of each traveler was surveyed by fifteen binary-choice questions that consisted of discounts/extras on tolls and changes in departure times. About 1,400 survey sheets were distributed at a service area of the motorway, and about twenty percent of which were mailed back. Parameters of an logit-model that includes socio-economic, trip and trip-reservation related attributes of travelers were identified based on the SP survey. The effect of the trip-reservation on the mitigation of the traffic congestion is to be quantitatively evaluated with the model. In Japan, very heavy traffic congestion of several ten kilo-meters in length occurs on trunk roads from four to five times a year mainly because people are likely to simultaneously take one-day or a-few-day holiday. It is not economically justified and hardly possible to increase road capacity in order to meet such peak traffic demand. The time fluctuations of traffic demand is rather to be leveled in order to decrease the imbalance between road capacity and traffic demand during the high-seasons. This study quantitatively searches a possibility that trip reservation systems can dissolve or reduce holiday traffic congestion on rural-motorways, which connect urban areas with resorts, by leveling time-fluctuations of traffic demand.
The idea of trip reservations was mentioned in REF within which trip reservations are proposed to relieve the holiday congestion problem on a rural motorway in a similar way as the train seat reservations.