A psychological approach to understand decisions about time in public transport. Evidence from lab experiments in London, UK and Santiago, Chile.

Author: Pablo Guarda

Journal: Submitted to the Department of Psychology and Language Sciences in partial fulfillment of the requirements for the degree of Master of Science at University College London


When presented with a choice of waiting another ten minutes for a bus or spending the same amount of time travelling, how would you decide? Strictly speaking, if an increase in waiting time (w) or in-vehicle time (v) produces the same difference in journey time (j), it may be argued that the impact of increases in w or v in passengers choices should be the same. However, passengers may sometimes prefer to travel more in order to wait less and as a consequence seemingly irrational behaviour may appear. Apart from the fact that passengers may dislike waiting, little has been explored about the underlying psychological processes behind trade-offs between waiting and travelling times.

Another relevant question in decisions about time in public transport is related to the impact of time variability. Transportation networks are complex and passengers used to experience high levels of time variability during their commuting trips. Besides the fact that people may dislike time variability, to our knowledge there is no evidence showing that the variability in waiting and travel times affects people’s decisions in the same manner. For instance, if you are asked to choose between bus routes where you experience the same amount of variability but either in waiting or travel times, which would you choose? Time variability may also mediate the dislike ofwaiting in public transport. For instance, passengersmay dislikewaiting more than travelling due to the higher variability of the former rather than the experience of waiting itself. A potential implication is that passengers may be indifferent between waiting or travelling in public transport systems that provides regular waiting times.

Here it becomes relevant to perform comparative studies on the travellers’ experience in different public transport systems to check if the standard assumptions about the valuation of waiting and travel times in transportation sciences remain valid. To empirically answer our research questions, we designed a computer-based experiment to understand how people decide between bus routes with different waiting and travel times. The experiment was conducted with 72 university students from London, UK and Santiago,
Chile. The data was first analised with statistical methods used in Psychology to measure the impact of different experimental manipulations. Subsequently, we estimated discrete choice models (DCM), the traditional approach in transportation sciences for modelling route choice. DCM allowed us to quantify the relative impact of changes in both the average and variability ofwaiting and travel times based on the sample of participants’ route choices. We expect that this multidisclipinary effort for integrating both theorethical and methodological frameworks from cognitive and transportation sciences will make a significant contribution to the existing research on decisions about time and it will also inform policy aiming at improving passengers’ experience in public transport systems.

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