Dynamics of demand in passenger services on railways

The dynamic effects are a long-term process concerning equilibrium between demand and supply that is usually not achieved in a few years, but after a significantly longer period that can be counted in decades. The consequences of the dynamics may be that society makes incorrect or undersized investments in the railway network based on non-dynamic models. This report examines what research has been conducted on when and to what extent dynamic development occurs in rail passenger demand, and whether any research has been conducted on modelling this dynamic development. Results showed that hard measures such as for example frequency of service, travel time and number of necessary interchanges have been studied to a large extent and it is well understood how such measures affect demand, especially in urban transport. However, literature has found that softer measures, which take longer time to have an effect on demand, could be responsible for some of the dynamic development and forecast inaccuracies found in the literature. Also, external factors that are often considered less or even excluded from models, were found to sometimes affect demand significantly. Another aspect is the rail factor, i.e. some mode specific attraction assigned to guided transport. The effect of the rail factor has been studied with very mixed results. It would however only be relevant to include the rail factor if there has been a change in modes or if there is competition between rail and road-bound modes such as a bus service. It has been clear during this work that not that much literature exists on this topic. The main conclusion of this report would therefore be that more work could be done to examine how dynamic effects affect passenger demand. This is especially true for the very long timespans of a couple of decades or more.