Measuring and improving the efficiency and effectiveness of bus public transport systems

In this paper, Data Envelopment Analysis (DEA) is used to evaluate the performance of individual bus lines composing the public transport network in Thessaloniki, Greece. Results showed that efficiency of local bus lines is slightly better than operational effectiveness without indicating a clear positive or negative relationship between the two performance components. Traffic conditions and population density seem to be important exogenous factors influencing performance. We employed bootstrapping techniques to check robustness of DEA results and we explain that performance assessment is more reliable when correcting for bias. We found that production models we developed for evaluating performance do not always exhibit the same technology of returns to scale, indicating that comparison across ratings pertaining to different performance dimensions should be made with caution. DEA results enabled us to perform clustering of bus lines based on the derived piecewise production functions. We defined the variables of these functions so as to allow performance improvement monitoring over service design changes in any given bus public transport network. It is found that for most of the bus lines in Thessaloniki, scheduling of buses with fewer seats would be a more successful performance improvement measure than reducing their span of service.