The efficiency of a transport system depends on several elements, such as available technology, governmental policies, the planning process, and control strategies. Indeed, the interaction between these elements is quite complex, leading to intractable decision making problems. The planning process and real-time control strategies have been widely studied in recent years, and there are several practical implementations with promising results. In this paper, we review the literature on Transit Network Planning problems and real-time control strategies suitable to bus transport systems. Our goal is to present a comprehensive review, emphasizing recent studies as well as works not addressed in previous reviews.

Planning, operation, and control of bus transport systems: A literature review

The dynamics of the ethnic residential distribution in the Yaffo area of Tel Aviv, which is jointly occupied by Arab and Jewish residents, is simulated by means of an entity-based (EB) model. EB models consider householders as separate entities, whose residential behavior is defined by the properties of the surrounding infrastructure and of other householders. The power of the EB approach lies in its ability to interpret directly different forms of decisionmaker behavior in the model's terms. Several scenarios of residential interactions between members of local ethnic groups are compared on the basis of detailed georeferenced data taken from Israel's 1995 Population Census. The model simulates very closely the residential dynamics during the period 1955^95; the importance of the qualitative aspects of residential choice, as captured by the EB approach, is demonstrated by this correspondence.

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Entity-based modeling of urban residential dynamics: The case of Yaffo, Tel Aviv

It is well known that coordinated, area-wide traffic signal control provides great potential for improvements in delays, safety, and environmental measures. However, an aspect of this problem that is commonly neglected in practice is the potentially confounding effect of drivers re-routing in response to changes in travel times on competing routes, brought about by the changes to the signal timings. This article considers the problem of optimizing signal green and cycle timings over an urban network, in such a way that the optimization anticipates the impact on traffic routing patterns. This is achieved by including a network equilibrium model as a constraint to the optimization. A Genetic Algorithm (GA) is devised for solving the resulting problem, using total travel time across the network as an illustrative fitness function, and with a widely used traffic simulation-assignment model providing the equilibrium flows. The procedure is applied to a case study of the city of Chester in the UK, and the performance of the algorithms is analyzed with respect to the parameters of the GA method. The results show a better performance of the signal timing as optimized by the GA method as compared to a method that does not consider rerouting. This improvement is found to be more significant with a more congested network whereas under a relatively mild congestion situation the improvement is not very clear.

/pdf/a-genetic-algorithm-approach-for-optimizing-traffic-control-3y5mfj0lr0.pdf

A genetic algorithm approach for optimizing traffic control signals considering routing

This article proposes to solve the oversatu- rated network traffic signal coordination problem us- ing the Ant Colony Optimization (ACO) algorithm. The traffic networks used are discrete time models which use green times at all the intersections throughout the consid- ered period of oversaturation as the decision variables. The ACO algorithm finds intelligent timing plans which take care of dissipation of queues and removal of block- ages as opposed tothe solecost minimization usually per- formed for undersaturation conditions. Two scenarios are considered and results are rigorously compared with solutions obtained using the genetic algorithm (GA), tra- ditionally employed to solve oversaturated conditions. ACO is shown to be consistently more effective for a larger number of trials and to provide more reliable so- lutions. Further, as a master-slave parallelism is possible for the nature of ACO algorithm, its implementation is suggested to reduce the overall execution time allowing the opportunity to solve real-time signal control systems. only a short time, the time to clear the network may be significant. Costs of infrastructure renewal and expan- sion may be cost prohibitive, and, under limited bud- gets, strategies are needed that enhance the mobility

Comparing Ant Colony Optimization and Genetic Algorithm Approaches for Solving Traffic Signal Coordination under Oversaturation Conditions

Publisher Summary This chapter reviews a survey on the operations research literature applied to the domain of public transit, with a focus on recent contributions. It highlights a fruitful cooperation between the public transit agencies and the operations research community. Indeed, public transit has provided interesting and challenging problems to operations research, while operations research has been successful at solving efficiently several important public transit problems—for example, network design, timetabling, vehicle scheduling, and crew scheduling. New problems—the integration of vehicle and crew scheduling, bus parking and dispatching, as well as a wide variety of real-time control problems—that presents new challenges to the operations research community have also been studied recently. Research on these problems has already suggested innovative models and solution methodologies, which might be applicable in practice in a near future. The main goal of most transit agencies is to offer to the population a service of good quality that allows passengers to travel easily at a low fare. The agencies, thus, have a social mission that aims at reducing pollution and traffic congestion as well as increasing the mobility of the population.

Chapter 2 Public Transit

A unified methodology has been proposed for the quantification of congestion, incorporating the volume and operational characteristics of traffic movement. The level of congestion has been modeled to relate to the causal influences of traffic movement. Modeling congestion has provided a quantitative basis for understanding the contribution of different vehicle types in overall congestion, and it is useful for evolving the policy for congestion mitigation. Quantified congestion level has been used as a logical and improved measure of effectiveness to account for the conceptual definition of level of service in a quantitative manner. Based on the congestion level, 10 levels of service have been proposed, with 9 in a stable flow zone (presently designated as \iA–\iE), and 1 representing an unstable operation (presently designated as \iF). The philosophy has been demonstrated by developing congestion models and assessing the effect of roadway width on congestion levels and service volumes. While it is possible to assess the realized benefits from an increase in roadway width, the required number of traffic lanes for a desired level of service can also be estimated.

Modeling congestion on urban roads and assessing level of service

In this paper a heuristic algorithm is discussed for development of feeder routes to railway stations. The heuristic algorithm is a part of a model that has been developed for operational integration of suburban railway stations and public buses. The model has two distinct components, the first part is development of feeder routes for public buses to suburban railway stations and the second part is determination of optimally coordinated schedules of feeder bus services for the given schedules of suburban trains. The second part of the model is beyond the scope of this paper. Andheri and Vileparle suburban railway stations on a western railway line in Mumbai, India were taken as study areas, and extensive data collection was done at these railway stations. Various nodes and their potential demands from these railway stations were identified, and the demand-deviated feeder routes were developed for Bombay Electric Supply and Transport buses, which are being used as public buses in Mumbai, India.

Development of feeder routes for suburban railway stations using heuristic approach

A grid based modelling approach akin to cellular automata (CA) is adopted for heterogeneous traffic flow simulation. The road space is divided into a grid of equally sized cells. Moreover, each vehicle type occupies one or more cell as per its size unlike CA traffic flow model where each vehicle is represented by a single cell. Model needs inputs such as vehicle size, its maximum speed, acceleration, deceleration, probability constants, and arrival pattern. The position and speed of the vehicles are assumed to be discrete. The speed of each vehicle changes according to its interactions with other vehicles, following some stochastic rules depending on the circumstances. The model is calibrated and validated using real data and VISSIM. The results indicate that grid based model can reasonably well simulate complex heterogeneous traffic as well as offers higher computational efficiency needed for real time application.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/atr.5670420404

Heterogeneous traffic flow modelling for an arterial using grid based approach

Suburban trains and public buses can play a better role in public transportation if they are coordinated Coordination of these two services will reduce the journeys made by intermediate public transport services and private vehicles from railway stations, which have become major traffic generators Thus, congestion, delays, and environmental pollution due to these services can be reduced to a great extent In this study, the Andheri and Vileparle suburban railway stations in Mumbai, India are taken as study locations, and schedule coordination between suburban trains and public buses [Bombay Electric and Suburban Transport (BEST) buses] at these suburban railway stations is attempted The coordinated schedules of BEST buses have been determined on already developed feeder routes for these two stations using the schedule optimization model (SOM) The objective function of the SOM is the minimization of transfer time between two services and vehicle operating costs of BEST buses The objective function and

Development of Coordinated Schedules using Genetic Algorithms

This paper discusses a model for developing optimal integrated schedules for urban rail and feeder bus operation. It consists of two parts: train scheduling submodel and schedule coordination submodel, which are formulated as combinatorial type optimization problems. The objective function for train scheduling submodel is fixed as minimization of sum of operating cost of trains (operator cost) and total waiting time cost of passengers boarding the train (user costs) subject to load factor and waiting time constraint, whereas the objective function for schedule coordination submodel is fixed as minimization of sum of total operating cost of feeder buses (operator cost), total transfer time cost for passengers transferring from train to feeder buses, and total waiting time cost of passengers boarding enroute (user costs) subject to load factor and transfer time constraint. The coordination is done for two cases: Case 1 for mixed fleet buses, considering all types of buses; Case 2 for single-decker fleet buses, considering only standard single-decker buses, and the results are compared to adopt the best strategy. Thane City, which is a part of Mumbai Metropolitan Region, India, is taken as the case study area. The coordinated feeder bus schedules were found to be optimum for the mixed fleet bus case.

S. L. Dhingra

Papers

Modeling congestion on urban roads and assessing level of service

Development of feeder routes for suburban railway stations using heuristic approach

Heterogeneous traffic flow modelling for an arterial using grid based approach

Development of Coordinated Schedules using Genetic Algorithms

Developing Integrated Schedules for Urban Rail and Feeder Bus Operation