Design of reliable schedules and control strategies for improving bus system performance

Resumen

High-level service bus systems, even though in many different forms and local particularities, have been spread out around the globe over the last decades, driven by the administration and the transport authority, and in close cooperation with the operator agencies. Under the common denominator of a higher-level service, those bus systems succeeded quite a lot anywhere due to the best performance of their operational indicators, such as service regularity, commercial speed, and time-headway. Nevertheless, many actions should be undertaken and applied to be able to supply all those benefits. Consistent with the above, this thesis defines several procedures enabling the design of reliable scheduled timetables and operating control strategies aimed at achieving an optimal operation. Also, more complicated route layouts, as in the case of transit corridors served by two routes, have been studied; and a specific methodology to evaluate the operational performance of the transfer areas has also been developed, as true cornerstones of those transfer-based bus networks. The first theme of this thesis consists of setting up a methodology for drawing up efficient timetables, optimising recovery times at the bus terminals, fulfilling on-time departures, according to a predefined statistical percentage, and minimising resources in terms of vehicles and drivers, observing operating rules and constraints. In the example of route H12 from Barcelona’s New Bus Network, travelling times could be adjusted and an increase by 40% of recovery time (from 5’ to 7’) could be implemented to be able to secure on-time departures. After reviewing how service regularity is calculated, according to the leading worldwide agencies and transport authorities, a procedure to detect the bus bunching is determined as well as various strategies to control and mitigate its effect, making possible the adherence to the scheduled headway, and keeping the bus carrousel well-regulated. Up to 40% improvement has reached applying a strategy that combines bus speed dynamic control with traffic signal priority at the intersections. The third issue is the operation of transit corridors served by two routes, a more complicated route scheme, advantageous to get a more efficient service -with optimal resource allocation- and to increase the service coverage. The objective is to keep the central section well-regulated and the studied headway adherence strategies are fundamental, although, as a general rule, an increase in resources is needed, which means in turn an increase of the agency costs. The fourth subject of this thesis focuses on the transfer areas and provides a tool to assess the operational quality of their transfers. For a wide range of layouts, the operating quality of the entire node can be evaluated as well, considering the contributions of each one of their connections, weighted by ridership. This methodology is fully transferable to other modes of transport, such as the railways.