sustainability Article What Makes Urban Transportation Efficient? Evidence from Subway Transfer Stations in Korea Changhee Kim 1 ID , Soo Wook Kim 1, Hee Jay Kang 1,* and Seung-Min Song 2 1 College of Business Administration, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul 08826, Korea;
[email protected] (C.K.);
[email protected] (S.W.K.) 2 Department of Child and Family Welfare, The University of Suwon, San 45, Wau-ri, Bongdam-eup, Hwasung, Kyunggi 18323, Korea;
[email protected] * Correspondence:
[email protected]; Tel.: +82-02-880-8594 Received: 17 September 2017; Accepted: 8 November 2017; Published: 9 November 2017 Abstract: Subway stations have been proliferating underneath cosmopolitan metropolises with subway lines forming complex webs connected in strategic transfer stations. The efficiency of the subway system thus heavily weighs on the efficiency at these transfer stations. However, few studies have been conducted on transfer efficiency at transfer stations due to the complexities involved. As the first study of its kind in the subway context, we analyze the transfer efficiency of the subway transfer stations in Seoul, one of the megacities in the world, and demonstrate how transfer efficiency can be analyzed using bootstrap-based DEA technique. Based on the results, we discuss the reasons behind the inefficiency of subway transfer stations and possible ways to improve them into efficient decision-making units. Keywords: urban transportation; subway transfer station; transfer efficiency 1. Introduction Urban public transportation is vital to the livelihood and dwelling of residents and commuters, who rely on public transportation to provide cheap, efficient, and convenient methods of travel for their daily use [1–3].