Seat reservation systems have been used for decades in train and air transport. Also, rail and air companies make a reservation of a slot on the network to ensure the availability of the scheduled path. The main goal of such a reservation system is to avoid queuing. Also, a reservation system combined with a system of scarcity pricing can be used to give priority to user groups with a higher willingness-to-pay in a situation of scarcity. This paper investigates the possible benefits of the implementation of slot allocation on motorway networks. Given a theoretical situation which satisfies a number of criteria, for instance ubiquitous availability of information, imposing scarcity tolls would be sufficient to attain a system optimal traffic equilibrium. However, due to many uncertainties, a system that forces users to state their preferences in advance might prove to be beneficial. Moreover, there are reasons to disbelieve that willingness-to-pay is equal to the utility of the trip. A slot allocation system might be a more efficient alternative to bridge the gap between user equilibrium and system optimal traffic patterns. After investigating the potential benefits of slot allocation in a qualitative way, the significance of some potential benefits will be analysed. It appears that especially in a situation with several user classes that differ with respect to aspects like value of time, delay costs and adjustment costs as well as vehicle characteristics, the benefits of introducing slot allocation on a road network might be significant.
Abstract