Evaluating the Dynamic Accessibility of Metro Systems in Overcrowded Conditions

Abstract

Metro accessibility is a concept used to describe the dynamic accessibility index of metro transportation systems. Most studies on accessibility apply a static approach, which overlooks the index fluctuations throughout the day. While it is possible to represent the accessibility using a single index, the ability to capture the dynamic nature of the index is important in understanding the quality of a transportation service and identify actionable aspects for improvement. For example, when the metro system is overcrowded and passengers fail to board the next arriving train, they instead wait for the subsequent train. As a result, the accessibility of the system is deemed to be lower than when its condition is uncrowded. This paper analyzes and integrates two aspects of metro accessibility: the performance of metro networks; and the dynamics of train schedules. An evaluation model in the form of a gravity model is proposed to measure the accessibility between each pair of stations with the dynamic travel time. This allows us to obtain profiles that highlight the daily variations in accessibility in the metro network and to identify the influence of congestion among stations. The effectiveness of the proposed evaluation model is validated using the metro network of Shenzhen in China. Results show that the proposed methodology provides useful information for passengers and travel guides as well as technical reference for the metro operation guidelines that are used to compile train schedules.

Optimizing bikeshare service to connect affordable housing units with transit service

“…To measure accessibility as a dynamic index by considering overcrowded conditions in metros, a gravity model that considered the capacity of a metro line, the number of passengers on a metro line real-time (using swipe in and swipe out counts of passengers at every stop) in addition to other factors like waiting time, the attractiveness of the destination was also used. This methodology helped them to estimate the real-time accessibility of an individual to a destination by metro at different times of the day (Li et al 2020). Bills and Carrel noted that most methodologies that calculated accessibility did not consider travel time unreliability which risks mischaracterization of the accessibility experienced by users.…”

GIS-Based Approach to Dynamic Accessibility: Incorporating a User Perspective to Recognize Social Equity Implications

“…GTFS datasets have been developed and used for planning, mobility monitoring, data visualization, timetable creation, and real-time information systems ( 24 ). GTFS data have been related to U.S. Census data at the census tract and block group level to show accessibility patterns at the national level ( 25 ) as well as being used at local and regional levels to identify gaps in public transit systems and demands based on the needs of the local population ( 26 ).…”

A Comprehensive Model to Study the Dynamic Accessibility of the Park & Ride System

“…The recent increase in techniques that allow for high-resolution data collection has led to the rise of studying dynamic accessibility that accurately captures temporal differences in accessibility over periods of time [24]. Dynamic accessibility, measured for travel times, relies on the various modes of transport and plays a significant role in varying times with shifts in the transport network and destinations of people's activities [25]. The outcomes of a dynamic accessibility measurement for public transport and private mode will be substantially different in different circumstances.…”