Circuity in China's high-speed-rail network

摘要

This study investigates the circuity of China's high-speed-rail (HSR) network from 2014 to 2016 and analyzes the network performance. The concept of circuity has been redefined in terms of travel time so that various speed levels of HSR lines can be measured systematically. In this study, circuity is redefined as the ratio of actual travel time to ideal travel time. By using actual HSR trip records, the influence of passenger demand and the circuity of transfer trips have been examined. At the node level, we find that the circuity of principal stations has significantly decreased overall. For stations with lower circuity, transfer trips from/to them tend to be more circuitous. Although stations along the intercity rail lines show higher circuity, they contribute to regional coverage and connectivity. Finally, we find that circuity tends to increase with a decreasing passenger flow for OD pairs within a certain distance range, and the passenger flow may decline as the OD distance increases.