Understanding risky choice behaviour with travel time variability: a review of recent empirical contributions of alternative behavioural theories

Stated choice analysis has been extensively applied to understand choice behavior with travel time variability. However, under a risk-neutral and belief-neutral assumption, the conventional approach to travel time variability has a number of behavioral limitations. In this review paper, we illustrate the violation of linear utility maximization under the traditional risk-neutral assumption and the violation of linear probability weighting under the belief-neutral assumption. This paper also reviews recent stated preference studies based on behaviorally superior theories (Expected Utility Theories, Rank-Dependent Utility Theory, Cumulative Prospect Theory) that have accommodated the role of risk attitude and/or belief in understanding risky travel choice behavior, including their behavioral contributions and major advancements over previous studies. We also highlight several common errors in the majority of the existing studies including the interpretation of risk attitude, the specification of nonlinear utility and the t-test for nonlinear probability weighting, and suggest ways to avoid these problems. Several avenues for future research are set out.