Measuring the transit benefits of accessibility with the integration of transit systems

Abstract

Transit systems create various benefits for society and the economy, which are commonly reflected in their accessibility. However, transit accessibility is not necessarily distributed fairly over space, resulting in spatial disparities in transit benefits. This study empirically examines the spatial distribution of transit benefits using accessibility measures specifically designed for public transit systems. To achieve this, a series of standardised transit benefit accessibility measures are developed and applied to the integrated transit systems in Seoul, South Korea, where bus and subway systems are seamlessly integrated via smartcard technology. Our measures assess the distributional impacts of transit integration. Our analysis revealed that transit benefits of accessibility have improved significantly in most areas of Seoul due to the integration of transit systems. However, these benefits have been realised as spatially disparate in Seoul. The findings stress the need for more equitable public transit policies to mitigate the identified spatial disparities.

KEYWORDS:

• Transit benefits of accessibility
• integrated transit system
• spatial disparity
• Seoul

Acknowledgements

This work was supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea (NRF-2018S1A5A8026828). We thank our research assistant Jihui Oh for collecting and cleaning data.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 Both bus and subway passengers tag their smartcard at their points of entry and exit to secure the right of free transfer and to allow the accurate calculation of transit fares based on travel distance. Thus, a journey is treated as beginning at the first entry of a bus or subway station and as ending at the station after which no more free transfers occur. Free transfers are allowed only when three conditions are met: (1) the alighting time from the previous vehicle is recorded, (2) the transferring vehicle was taken within 30 min, and (3) a different route or mode was used than was previously used. Unless all three conditions are satisfied, the system considers the trip to be a separate journey.

2 The Seoul Metropolitan Government uses five categories to calculate modal share, which are private vehicle, bus, subway, taxi, and others. Other modes include walking, cycling, and scooters. Public transit in this paper includes only the bus and subway because they are the only shared passenger modes accessible by the general public at a reasonable cost.

3 Basic fare is applied to journeys less than 10 km, and fare increased by 100 won (about 10 cents in US dollars) every additional 5 km traveled.

Additional information

Funding

This work was supported by National Research Foundation of Korea: [Grant Number NRF-2018S1A5A8026828].