Run-time delays in Indian Railways: is traffic the cause?

The Indian Railways (IR) has recently come under intense criticism for not being able to efficiently handle the rapidly increasing amounts of traffic, which is manifested in large run-time delays of trains. Motivated by this situation, we perform a statistical analysis of the run-time delays of express trains in IR. We find that trains in some specific geographical regions, such as the Indo-Gangetic plain, regularly experience high delays, indicating high congestion in these regions. However, rather surprisingly, the amount of traffic alone cannot explain the geographical variation of delays in IR. We also identify that the IR time-table contains significant slack, whereby trains running on certain segments frequently traverse the segments in lesser time than is scheduled. To our knowledge, this is the first study on the run-time delays of trains in IR. We also develop a Web-based application for visualizing traffic-flow in IR.