Modelling rain effects on risk-taking behaviours of multi-user classes in road networks with uncertainty

This paper proposes a new travel time reliability-based traffic assignment model to investigate the rain effects on risk-taking behaviours of different road users in networks with day-to-day demand fluctuations and variations in travel time. A generalized link travel time function is used to capture the rain effects on vehicle travel times and road conditions. This function is further incorporated into daily demand variations to investigate those travel time variations arising from demand uncertainty and rain condition. In view of these rain effects, road users' perception errors on travel times and risk-taking behaviours on path choices are incorporated in the proposed model with the use of a logit-based stochastic user equilibrium framework. This new model is formulated as a variational inequality problem in terms of path flows. A numerical example is used to illustrate the application of the proposed model for assessment of the rain effects on road networks with uncertainty.