Incorporating service reliability in public transport design and performance requirements: International survey results and recommendations

Although public transport passengers consider service reliability a key quality aspect, actual services are often not perceived as reliable. To gain insights into how authorities deal with (improving) service reliability, an international survey was performed, showing that very little attention is paid to service reliability during the design of the network and of the timetable. It also illustrates that there is little consistency in approaches. In addition, a second survey was performed, showing how Dutch authorities deal with service reliability in relation to concession requirements and incentive regimes. The main findings are that consistency is lacking on this topic and that minimum attention is paid to passenger impacts of unreliability in concession requirements. This results in services that do not match the (implicitly) required level of service reliability. These surveys also revealed that there is no consistency in the definition of service reliability. For instance, traditional indicators focus on vehicles instead of passengers. By using an alternative reliability indicator, additional travel time, we demonstrated that traditional indicators lead to wrong indications. Based on our findings, we present recommendations to improve concession requirements as well as to improve the design of networks and of timetables, both aiming at enhanced service reliability.