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Bus or Rail: An Approach to Explain the Psychological Rail Factor

Many public transport studies have found that potential passengers consider rail-based public transport to be superior to bus systems. Why is this? Two studies have been completed in Germany and Switzerland in search of explanations for this so-called psychological rail factor. In this article, these two studies are presented and discussed to introduce the schemata approach and to help identify differences of attributions towards rail- and bus-based public transport. The research found a psychological rail factor (i.e., a preference for using rail assum­ing equal service conditions) of 63 percent for regional train and 75 percent for trams compared to bus services. The rail factor is highly loaded with emotional and social attributions. They account for 20–50 percent of the share in the different schemata for bus, rail, and tram.


It is recognized that hard factors such as travel time, cost, availability of public transport services, and car ownership have a major impact when people consider the choice between using an automobile or public transport. Nevertheless, there is evidence from the literature that rail-based public transport often is considered superior to bus systems, even in cases where quantitative hard factors are equal. This attraction of passengers is known as a psychological rail factor, and it is used to express a higher attraction in terms of higher ridership of rail-based public transport in contrast to bus services (Axhausen et al. 2001; Megel 2001b; Ben-Akiva and Morikawa 2002; Vuchic 2005; Scherer 2010a). The existence of this rail factor is widely accepted among experts, but little evidence exists about the reasons for this phenomena.

The idea of a rail factor is consistent with statements that the image of a transport system has an impact on demand. Furthermore, research shows that transport characteristics often are misperceived (or misbelieved) and that costs are ranked less important by users making mode choice decisions than planners expect. This raises the question of how public transport characteristics are perceived and val­ued and which attributions are made towards different transport modes (Beale and Bonsall 2007; Guiver 2007). While many efforts have been undertaken to ana­lyze customer attributions towards car and public transport in general, only a few studies distinguish between different public transport modes (e.g., Megel 2001a; Cain et al. 2009).

It is expected that the images of different public transport systems vary between regions since customer attributions derive from perceptions and beliefs, which are influenced by local conditions and different cultures (Scherer 2010a). Thus, in addition to investigating attributions toward public transport modes in general, it is of interest to explore these attributions against the background of different spatial areas. The two case studies presented in this article explore differences in attributions towards train, tram, and bus in Germany and Switzerland to enhance the knowledge about different images of public transport systems.