THE RELIABILITY OF THE TRANSPORTATION SYSTEM AND ITS INFLUENCE ON THE CHOICE BEHAVIOR

This paper describes how, the expected reliability of a route, a transportation mode or a destination is one of the main variables when planning a trip or even a whole day. The route choice and the mode choice coheres with the choice of the departure time to reach a destination in time with an acceptable probability. The destination choice depends on the probability of the possibility to achieve the planned objectives (shopping, activities, etc.) at this place within a given time budget. In fact there is an obvious influence of the reliability but it is rarely implemented as a factor in current choice models. This neglect has got serious consequences in terms of political decisions for transport planning and the actions of public transport providers. For example, it might lead to the construction of roads with unsatisfactory capacities, because the cost-benefit-analysis do not contain the costs of the reliability. In the field of public transport speed will be overemphasized instead of investing into the vehicle pool or into keeping a staff reserve. Time tables might imply faster but also unrealistic and unreliable travel times. One main reason for this neglect is the difficulty of measuring the reliability. The main objective of this paper is to include reliability as a factor into choice models, estimate a value of the reliability, and give recommendations for more research.