Analysis of the Efficiency of Seoul Arterial Bus Routes and Its Determinant Factors

In this study, we constructed a network Data Envelopment Analysis (DEA) model to improve the existing bus service evaluation system in other to achieve a more realistic result than previous studies by considering both the desirable and the undesirable outputs. Based on the model, we estimated the efficiency of the 113 Arterial Bus routes in the city of Seoul in the year of 2009. It is assumed that each Decision Making Unit (DMU) uses inputs such as possession and operating costs, the ratio of median bus stops, and overlapped route lengths to produce both desirable outputs such as total riders and service satisfaction scores as well as undesirable outputs such as CO2 emissions. The analysis demonstrated that the model considering both the desirable and the undesirable outputs deduced more realistic results than its counterpart solely based on the desirable outputs. The bias and the confidence intervals of the efficiency estimates derived from the proposed DEA analysis are presented. The bootstrap method was employed to yield a dependent variable for the truncated regression model. The truncated regression analysis was conducted to analyze the determinant factors that influce the efficiency, which revealed that the possession costs and the ratio of median bus stops are ststistically significant factors.