Optimal operational strategies for single bus lines using network-based method

Abstract

As a shared transport mode, public transit is important for leading transportation systems to develop in a sustainable manner. It is well known that the passenger demand along a bus line fluctuates throughout the day and is not distributed uniformly, both temporally and spatially. This non-uniformity warrants the use of multiple operational strategies to enhance the efficiency of public transit service and further to facilitate sustainability, compared to a full route operation (FRO) strategy currently used worldwide. This study proposes a new network-based methodology for optimizing multiple operational strategies to accommodate the fluctuated passenger demand, based on a complete timetable using the FRO strategy. Four possible strategies are considered for a single-line bus operation: FRO, limited-stop, short-turn, and a combination of the latter two strategies. The methodology is based on a minimum-cost network-based model constructed by adjusting vehicle departures extracted from the complete timetable at determined stops. The cost on each network arc consists of the change in passenger travel time caused by the adjustment of vehicle departures, compared with the planned departures using the FRO strategy. The network-based problem, including special constraints, is solved by constructing an equivalent directed network of a particular pattern. The proposed methodology is first applied to a numerical example and then to a real-life bus line in Dalian, China. The results of the case study show that compared with the current FRO operation, the implementation of a combination of operational strategies reduces the total vehicle time by one bus trip and empty-seat time by approximately 50%.

Keywords:

• Network-based methodology
• operational efficiency
• operational strategies
• public transit

Additional information

Funding

The authors are grateful for the support of the National Natural Science Foundation of China [Grants: 71801027, 71431003] and partially by the Fundamental Research Funds for the Central Universities [Grants: 3132020162, 3132019301], and Lloyd's Register Foundation (Grant: G\100111), a charity that helps to protect life and property by supporting engineering-related education, public engagement, and the application of research. Any opinions, findings, and conclusions or recommendations expressed in this paper are those of the authors and do not necessarily reflect the views of the aforementioned funding bodies.