Integrated Optimization of Bus Line Fare and Operational Strategies Using Elastic Demand

An optimization approach for designing a transit service system is proposed. Its objective would be the maximization of total social welfare, by providing a profitable fare structure and tailoring operational strategies to passenger demand. These operational strategies include full route operation (FRO), limited stop, short turn, and a mix of the latter two strategies. The demand function is formulated to reflect the attributes of these strategies, in-vehicle crowding, and fare effects on demand variation. The fare is either a flat fare or a differential fare structure; the latter is based on trip distance and achieved service levels. This proposed methodology is applied to a case study of Dalian, China. The optimal results indicate that an optimal combination of operational strategies integrated with a differential fare structure results in the highest potential for increasing total social welfare, if the value of parameter ε related to additional service fee is low. When this value increases up to more than a threshold, strategies with a flat fare show greater benefits. If this value increases beyond yet another threshold, the use of skipped stop strategies is not recommended

Optimal Multi-Vehicle Type Transit Timetabling and Vehicle Scheduling

The public-transport (transit) operation planning process commonly includes four basic activities, usually performed in sequence: network design, timetable development, vehicle scheduling, and crew scheduling. This work addresses two activities: timetable development and vehicle-scheduling with different vehicles types. Alternative timetables are constructed with either even headways, but not necessarily even passenger loads or even average passenger loads, but not even headways. A method to construct timetables with the combination of both even-headway and even-load concepts is developed for multi-vehicle sizes. The vehicle-scheduling problem is based on given sets of trips and vehicle types arranged in decreasing order of vehicle cost. This problem can be formulated as a cost-flow network problem with an NP-hard complexity level. Thus, a heuristic algorithm is developed. A few examples are used as an expository device to illustrate the procedures developed

Public-transport vehicle scheduling with multi vehicle type

The public-transport (transit) operation planning process commonly includes four basic activities, usually performed in sequence: (1) network route design, (2) timetable development, (3) vehicle scheduling, and (4) crew scheduling. The purpose of this work is to address the vehicle scheduling problem, while taking into account the association between the characteristics of each trip (urban, peripheral, inter-city, etc.) and the vehicle type required for the particular trip. The problem is based on given sets of trips and vehicle types, where the categories are arranged in decreasing order of vehicle cost. Therefore, each trip can be carried out by its vehicle type, or by other types listed in prior order. This problem can be formulated as a cost-flow network problem with an NP-hard complexity level. Thus, a heuristic algorithm is developed in this work, based on the Deficit Function theory. Two examples are used as an expository device to illustrate the procedures developed, along with a real-life example of a bus company

The growth engine: Interconnecting transport performance, the economy and the environment

Public-transport (PT) timetables and their compliance mirror the quality of the PT service provided. Hence, vehicles departing too early or ahead of schedule need to be restrained, just as those leaving late must be scheduled or rescheduled to be on time. Because of existing problems of PT reliability, there is need to improve the correspondence of vehicle-departure times with passenger demand instead of assuming that passengers will adjust themselves to given timetables (excluding situations characterized by short headways). With the advance in technology of passenger information systems, the importance of even and clock headways is reduced. This allows for the possibility to create more efficient schedules from both the passenger and operator perspectives. This work contains a methodology framework with developed algorithms for the derivation of vehicle departure times (timetable) with either even headways or even average loads and with a smoothing consideration in the transition between time periods. The procedures presented are accompanied by examples and clear graphical explanations. It is emphasized that the PT timetable is one of the predominant bridges between the operator (and community) and the passengers, and thus its improvement will increase the level-ofservice for the PT passengers

Multiobjective Approach to Creating Bus Timetables with Multiple Vehicle Types

In times of climate change and scarce resources, it is essential to reduce emissions and to use fuel as economically as possible. The transportation sector alone accounts for 44% of the energy use in New Zealand, with only about one-quarter of that amount being used by the transportation industry for transporting goods. Therefore, an attractive public transport service and prudent use of its vehicles can help make travel more economical, thus saving resources and reducing carbon dioxide emissions. How to make public bus services more attractive is demonstrated with two simultaneous objectives: minimizing the expected passenger waiting time and minimizing the discrepancy from a desired occupancy level on the vehicles. The first objective is intended to improve the service and attract more users, and the second objective is intended to ensure economical operation. A network-based procedure is used to create timetables with multiple vehicle types to solve this multiobjective problem. The method is applied to a case study in Auckland, New Zealand, and results in a savings of more than 43% of passenger waiting time while attaining an acceptable passenger load on all vehicles

Public transport vehicle scheduling featuring multiple vehicle types

Vehicle scheduling is a crucial step of the public transport planning process because it results in the number of vehicles required, thus it is directly related to fixed cost and labor cost. It is desirable, therefore, to minimize the number of vehicles used and operational cost. This paper proposes a new methodology for the multiple vehicle types vehicle scheduling problem (MVT-VSP). The methodology is based on a minimum-cost network flow model utilizing sets of Pareto-optimal timetables for individual bus lines. Given a fixed fleet size the suggested methodology also allows a selection of the optimal timetable. The method developed enables to stipulate the use of a particular vehicle type for a trip or to allow for a substitution either by a larger vehicle or a combination of smaller vehicles with the same or higher total capacity. Moreover, a variation of the method portrayed makes it possible to construct sub-optimal timetables given a reduction of the vehicle-scheduling cost. It is demonstrated that a substitution of vehicles is beneficial and can lead to significant cost reductions in the range of more than 27%. The suggested methodology is applied to a real-life case study in Auckland, New Zealand, and the results show improvements of greater than 15% in terms of the cost of fleet compared with vehicle schedules that are provided by standard models

Communication-Based Cooperative Control Strategy for Public Transport Transfer Synchronization

Synchronized transfers in public transport (PT) networks are used to reduce interroute or intermodal passenger transfer waiting time and to provide well-connected PT services. However, in practice, it is well known that synchronized transfers do not always occur because of stochastic and uncertain factors such as traffic disturbances and disruptions, fluctuations in passenger demand, and erroneous behavior on the part of PT drivers. This paper proposes a communication-based cooperative control (CCC) strategy, which has its basis in a library of selected operational tactics (e.g., skip stop or station, holding, changes in speed) to increase the actual occurrence of synchronized transfers and thus reduce average passenger transfer waiting time. The performance of the CCC strategy was compared with three other control strategies, namely, the without control strategy, the conventional schedule-based control strategy, and the communication-based noncooperative control strategy, according to various system performance indicators. A Monte Carlo method-based simulation procedure was developed to address the endogenous randomness in vehicle travel time, passenger demand, and driver behavior. The proposed methodology was applied to a detailed example network and in a case study in Auckland, New Zealand. The simulation and optimization results showed that, compared with the other three strategies, the CCC strategy performed best to increase the actual occurrence of planned synchronized transfers, reduce the average passenger transfer waiting time, and reduce the vehicle bunching percentage. Thus the CCC strategy shows great potential to increase the efficiency of PT networks, which involves synchronized transfers, and ultimately to improve the attractiveness of PT service

Analysis of a new public-transport-service concept: Customized bus in China

In recent years, an innovative mode of public transport (PT) service, known as customized bus (CB), has been springing up across China. This service, providing advanced, personalized and flexible demand-responsive PT, is offered to specific clientele, especially commuters. The present work analyzes, for the first time, the evolution of this new PT concept across 30 Chinese cities where CB systems are currently in operation or under construction. Unlike conventional bus transit service, CB users are actively involved in various operational planning activities. CB personalizes PT service by using interactive and integrated information platforms, such as internet website, telephone and smartphone. The analysis comprises three components: first, a comprehensive examination of the background of CB and its temporal and spatial distribution in China; second, an analysis of the operation-planning process, including elements of online demand collection, network route design, timetable development, vehicle scheduling, crew scheduling, real-time control, and fare design and collection: third, a summary of the results of the examination and analysis, presenting pros, cons and recommendations. The successful implementation of CB in China demonstrates that this new PT service concept can effectively meet the ever-increasing mobility needs of large populations nation-wide. Similarly, the present work can provide a valuable reference for policymakers, academic researchers, PT practitioners and others worldwide

Battery-electric transit vehicle scheduling with optimal number of stationary chargers

Because of zero emissions and other social and economic benefits, electric vehicles (EVs) are currently being introduced in more and more transit agencies around the world. One of the most challenging tasks involves efficiently scheduling a set of EVs considering the limited driving range and charging requirement constraints. This study examines the battery-electric transit vehicle scheduling problem (BET-VSP) with stationary battery chargers installed at transit terminal stations. Two equivalent versions of mathematical formulations of the problem are provided. The first formulation is based on the deficit function theory, and the second formulation is an equivalent bi-objective integer programming model. The first objective of the math-programming optimization is to minimize the total number of EVs required, while the second objective is to minimize the total number of battery chargers required. To solve this bi-objective BET-VSP, two solution methods are developed. First, a lexicographic method-based two-stage construction-and-optimization solution procedure is proposed. Second, an adjusted max-flow solution method is developed. Three numerical examples are used as an expository device to illustrate the solution methods, together with a real-life case study in Singapore. The results demonstrate that the proposed math-programming models and solution methods are effective and have the potential to be applied in solving large-scale real-world BET-VSPs

Optimal Connected Urban Bus Network of Priority Lanes

This paper presents a new approach and modeling for selecting an optimal network of public transport (PT) priority lanes. Bus priority schemes and techniques on urban roads and highways have proved effective for almost half a century. Many bus priority studies have been published and demonstrated worldwide, but none has dealt with optimal connected networks of PT priority lanes. The approach used in this study was based on a systemwide concept to obtain optimal PT network coverage. Such a PT priority lane network would enable fast and less interrupted vehicle movement, would increase the reliability of transfers, and would provide better adherence to schedule performance. The study developed a model for the optimal selection of a set of PT priority lanes that maximized the total travel time savings and, at the same time, maintained balanced origin and destination terminals, given a budget constraint. An efficient CPLEX model was developed and tested. The model was used in a case study of Petah Tikva, a midsize city in Israel, and produced a successful, optimal network of priority lanes