Assessing Travel Time Reliability of Public Transport in Kolkata: A Case Study

Punctuality of a trip maker directly depends on the on-time performance of the whole transportation system and specifically on the travel time reliability of the preferred mode of transport. As a matter of this fact, daily commuters prefer a reliable mode of transport which adheres to its schedule and is frequently available. Thus, the present study aims to find only the travel time reliability of the different public transport modes in a particular route of Kolkata Metropolitan Area. The route from Bansdroni Bazar Area to Park Street Area was chosen as the case study area. The in-vehicle travel time reliability of the state government bus, private bus and minibus were estimated using the method proposed by Liu and Sinha [15] and the results compared with that of the metro railway. The result of the analysis shows that the travel time reliability of all bus types ranges from 45 to 65% of the reliability of the metro railway. The parameters prescribed by FHWA, such as Buffer Time (TB), Buffer Index (Bi), Planning Time (Pt) and Planning Time Index (Pi), were also estimated which provides valuable information about the reliability of the buses plying on the route under study. Delay parameters in transit contribute a lot to the travel time which was also observed to indicate the reliability of buses from delay perspective. The effects of some other relevant traffic parameters such as the congestion delay and waiting time delay on reliability have also been discussed as well.