Bus rapid transit operation analysis using the Downs–Thomson paradox Seungjae Lee 1 , Seungkyu Ryu 2 * and Shinhae Lee 3 1 Department of Transportation Engineering, University of Seoul, Seoul, Korea 2 Department of Civil and Environmental Engineering, Utah State University, Logan, UT, U.S.A. 3 Department of Transportation, Seoul Development Institute, Seoul, Korea SUMMARY The purpose of the paper is to analyze effectiveness before and after implementation of the bus rapid transit operation. The paper includes a speed analysis based on the Downs–Thomson paradox, and a reliability analysis based on variance analysis of arrival time. According to the speed analysis, some road sections are now under phase 2 in the Downs–Thomson paradox, which is a state in which the bus speeds are greater than the auto speeds. In the future, it is predicted that autos and buses will reach an equilibrium speed which is in phase 3 of the multi-modal equilibrium theory. According to the reliability analysis of arrival time at each bus stop, in roads of median arterial bus lanes, the variance of arrival time is generally smaller than after the scheme implemented in 8 months later. Copyright # 2010 John Wiley & Sons, Ltd. KEY WORDS: bus rapid transit operation; Downs–Thomson paradox; reliability analysis of arrival time 1. INTRODUCTION The most common practical policy for reducing the social total travel time in a transport network is to increase road capacities by building new roads or expanding more lanes for car users. However, the increasing road capacity in many cases leads to cause an increase in travel costs which contradicts the primal intention because extending capacity could induce more travel demand on the road. It is generally called Downs–Thomson paradox. This paradox indicates that public transport oriented policies can be only effective to relieve traffic congestions in urban areas. Therefore the government of Seoul has operated an exclusive bus lane to improve the efficiency of public transport since 1984. Nevertheless, buses were interrupted by the maneuvers of other vehicles’ turning, stopping, and parking in the bus lane because the bus lane was provided only in the curb lane. In order to make the system better, the government has set up a bus rapid transit operation by providing a median arterial bus lane initially only for 4.5 km in 1996 and then extended to total 32 km in July 2004, which can now cover major trunk corridors towards CBD areas of Seoul. The purpose of paper is therefore to analyze the effectiveness of the bus rapid transit operation by providing the median arterial bus lane in terms of comparing speeds and arrival times for morning peak hours in terms of before and after the median arterial bus lane operation. The speed analysis is conducted logically through the Downs–Thomson paradox. According to Transit Capacity and Quality of Service Manual (TCQSM) of TCRP Report [1], there are many performance measures for public transport such as reliability, travel time, waiting time, safety and security service. In the paper we use an effective analysis of waiting times at bus stops by using bus arrival time data in relation to the TCQSM mobility measures. The various data of buses can be collected accurately because of the Bus Management Systems (BMS) that have been established in July 2004. The data set used in the paper is obtained from Global JOURNAL OF ADVANCED TRANSPORTATION J. Adv. Transp. 2010; 44: 205–215 Published online 2 July 2010 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/atr.139 *Correspondence to: Seungkyu Ryu, Department of Civil and Environmental Engineering, Utah State University, Logan, UT, U.S.A. E-mail: seungkyu.ryu@aggiemail.usu.edu Copyright # 2010 John Wiley & Sons, Ltd.