Mitigating road work disruptions on bus service : a framework for passenger impact evaluation

Abstract

Road works are increasingly disrupting the operations on London's TfL bus network, increasing running times, running time variability, and headways. Operators manage disruptions by short-turning more often, making passengers have longer and less reliable journeys. Mitigation strategies are put in place to limit the impact of these disruptions, such as by increasing scheduled headways or fleet size, systematically curtailing trips, or diverting the route to avoid traffic around the construction site. These mitigation strategies can themselves impact passengers. This research introduces a framework to analyze and evaluate the potential impacts of disruptions and mitigation strategies on bus passenger demand, utilizing automatically collected data. A post-hoc analysis of road work impacts highlights the need to examine the impacts of road works on different origin-destination market segments within the impacted bus routes. Changes in performance measures are difficult to explain without accounting for exogenous factors, suggesting that it would be challenging to develop a credible model for predicting route performance metrics. A framework is developed to model and predict the demand response to bus route service changes. A methodology to evaluate mitigation strategies is presented, and an itinerary choice model is developed and calibrated on data covering the entire TfL network. A pilot implementation is built as a web application with interactive maps and dashboards. The framework is tested by studying past road works on a bus route in London. The mitigation strategy that was actually applied is evaluated with the model, and the performance estimates are compared to historical data, validating the framework and identifying ways in which the model could be improved. The benefits of using the framework to compare potential service changes are illustrated by evaluating two alternative mitigation proposals for the case study. The visualization tool enables a quick analysis of critical zones for passengers, which guides strategy design, and performance metrics structure the evaluation of service change proposals.