Taking the path less travelled: Valuation of denied boarding in crowded public transport systems

Many public transport networks worldwide experience high crowding levels. Overcrowding can result in passengers not able to board the first arriving vehicle. We infer how waiting time induced by being denied boarding in crowded public transport systems is valued by passengers, based on observed passenger route choice behaviour. For this purpose, we estimate a revealed preference route choice model based on passenger and vehicle movement data. As denied boarding typically occurs only at specific locations and within strict time bands, whilst its occurrence is notoriously uncertain, we propose additional constraints to generate an appropriate choice set for which observed route choices can be used to estimate denied boarding perceptions. We found that the additional waiting time caused by denied boarding is valued 68% more negatively compared to the initial waiting time. On average, one minute of initial and denied boarding wait time are perceived as 1.62 and 2.72 min on-board an uncrowded vehicle, respectively. Not incorporating this more negative denied boarding wait time valuation can result in an underestimation of the passenger and societal impact of overcrowding in public transport systems. Moreover, it can underestimate the benefits of potential crowding relief measures and as such underestimate the benefit-cost ratio of these measures.