En-route headway-based bus reliability with real-time data at network scale

Yiyi Li,Huadong Tan

doi:10.1093/tse/tdaa017

Abstract

AbstractBus reliability has long attracted attention and been extensively studied to enhance service quality. However, existing research generally evaluates bus reliability of specific routes or stops. To this end, this study explores en-route bus reliability with real-time data at network scale. Drawing on data of bus automatic vehicle location and smart card usage in Ningbo, China, this study calculates headway-based reliability with the difference between actual and scheduled headway at each stop. To demonstrate the trend of stop-level reliability along a bus route, reliability is graded and visualized on a map with ridership at each stop, which is then weighted with passenger-boarding volume. Route-level reliability is then quantified and mapped, where unreliable service basically concentrates in or extends through the centre area. With respect to network-level reliability, temporal changes are demonstrated with ridership on weekdays and at the weekend. It is observed that on weekdays, the reliability trend is similar to that of ridership, implying a causal relationship between bus travel-time variation and bus waiting-time at stops. Furthermore, a reliability comparison between weekdays in December and October shows the necessity of evaluating periodically and around important events to avoid negative riding experiences that discourage public transport usage. This research provides insights for bus agencies to systematically evaluate service reliability both spatially and temporarily, in order to identify and prioritize the routes and stops where the scope for reliability improvement and the expected benefit are greatest.

Highlights

Urban transportation has become increasingly congested and vehicle pollution is seriously affecting city environments
This study explores en-route bus reliability with real-time data at network scale
Drawing on bus automatic vehicle location (AVL) and smart card data, this research contributes the evaluation of stop-level reliability at network-scale, which is headway-based due to the absence of timetable

Summary

Introduction

Urban transportation has become increasingly congested and vehicle pollution is seriously affecting city environments. Travel demand and trip length will continue to increase, intensifying the conflict between transport supply and travel demand. To address this problem, it is a well-accepted remedy to develop public transport to carry more passengers at one time. As bus mostly operates on unseparated lanes, travel time is open to various disruptions and buses may arrive at stops irregularly, which increases waiting time and passenger anxiety, causes excessive bus-waiting time and severe in-vehicle crowding, and may risk travellers missing planned activities. Current evaluation methods generally focus on few routes or stops with limited data, and fail to comprehensively evaluate bus service reliability from a system perspective.

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