Multi-modal and demand-responsive passenger transport systems: a modelling framework with embedded control systems

The LITRES-2 modelling system provides a framework for investigating the performance of urban passenger transport systems, with particular attention to demand-responsive transport modes and traveller information technologies. The modes covered include conventional timetabled services (buses, trains etc.), taxis (both single- and multiple-hire), and other demand-responsive services. Tables of estimated aggregate demand are disaggregated so as to produce a stream of fully-articulated travel-requests. Individual requests are resolved as single- or multiple-leg journeys, through the use of request-broking and journey-planning modules that seek to minimise travellers' generalised costs. Journey-legs allocated to demand-responsive modes are handled by a fleet-scheduling module which includes provision for “instantaneous” as well as advance-notice bookings, and for contingent situations such as breakdowns and passenger no-shows. The fleet-scheduling and journey-planning modules are designed as embedded control systems and are intended for use in real-time as well as modelling applications. The paper describes the main analytical and procedural components of LITRES-2, and assesses some methodological issues arising from experience in recent planning studies. The system appears to be well suited for use in modelling situations where the critical issues are concerned with the supply rather than demand side of transportation activity.     

ITS applications in public transport: Improving the service to the transport system

This paper examines all the disparate technologies and techniques capable of smoothing the integration of public transport modes and services at both the urban and interurban scale. The paper focuses on the application of information technology and telematics solutions which have been designed to create as seamless a journey as possible from the point of view of the transport system user. The scope of the paper is therefore deliberately wide‐ranging and includes an examination of measures as apparently unconnected as smartcard ticketing, bus priority systems, automatic vehicle locationing, trip planning and on‐board information systems as well as new public transport services offering demand responsive travel and integration with taxi services. The paper intends to show how such technological solutions can be used to increase the attractiveness and competitiveness of fixed public transport networks in comparison to the door‐to‐door flexibility of the private car.     

Modal split and urban public transport management in an Eastern European country

When public transport is the main means of travel in urban areas, management and planning are easy and the main objective can be to minimise costs for the demand available, i.e. maximise profit. However when public transport faces competition from other modes of transport, and activities can be undertaken in a variety of locations, then the management and planning of public transport services is considerably more difficult.This paper examines a methodology for representing consumer behaviour when faced with alternative travel decisions, in order to identify the demand for public transport and to help operators adjust services and prices to maximise demand, when considering people's disposable income, the alternative modes and activity locations available. From this it is possible to devise criteria for maximising consumer surplus in a city, taking into account social benefits.     

Fleet scheduling and dispatching for demand-responsive passenger services

This paper describes a software system designed to manage the deployment of a fleet of demand-responsive passenger vehicles such as taxis or variably routed buses. Multiple modes of operation are supported both for the fleet and for individual vehicles. Booking requests can be immediate (i.e. with zero notice) or in advance of travel. An initial implementation is chosen for each incoming request, subject to time-window and other constraints, and with an objective of minimising additional travel time or maximising a surrogate for future fleet capacity. This incremental insertion scheme is supplemented by post-insert improvement procedures, a periodically executed steepest-descent improvement procedure applied to the fleet as a whole, and a “rank-homing” heuristic incorporating information about future patterns of demand. A simple objective for trip-insertion and other scheduling operations is based on localised minimisation of travel time, while an alternative incorporating occupancy ratios has a more strategic orientation. Apart from its scheduling functions, the system includes automated vehicle dispatching procedures designed to achieve a favourable combination of customer service and efficiency of vehicle deployment. Provision is made for a variety of contingencies, including travel slower or faster than expected, unexpected vehicle locations, vehicle breakdowns and trip cancellations. Simulation tests indicate that the improvement procedures yield substantial efficiencies over more naı̈ve scheduling methods and that the system will be effective in real-time applications.     

The bicycle as a feedering mode: experiences from three European countries

Bike-and-ride, or the combined use of bicycle and public transport for one trip, is a multimodal alternative for the car. This paper discusses the use of bike-and-ride in three countries with widely differing bicycle cultures and infrastructures: the Netherlands, Germany and the UK. The share of the bicycle in access trips is comparable to general levels of bicycle ridership in each country, but only for train services and other fast modes of public transport. Strong similarities are found in the characteristics of bike-and-ride trips and users, in terms of travel distances, travel motives, and the impact of car availability. The majority of bike-and-ride users travels between 2 and 5 km to a public transport stop, with longer access distances reported for faster modes of public transport. Work and education are the main travel motives, with the first dominating the faster modes and the second the slower modes of public transport. Car availability hardly influences the choice for a combined use of bicycle and train, but strongly affects the levels of bike-and-ride for slower modes of transport.     

A systematic analysis of multimodal transport systems with road space distribution and responsive bus service

A smart design of transport systems involves efficient use and allocation of the limited urban road capacity in the multimodal environment. This paper intends to understand the system-wide effect of dividing the road space to the private and public transport modes and how the public transport service provider responds to the space changes. To this end, the bimodal dynamic user equilibrium is formulated for separated road space. The Macroscopic Fundamental Diagram (MFD) model is employed to depict the dynamics of the automobile traffic for its state-dependent feature, its inclusion of hypercongestion, and its advantage of capturing network topology. The delay of a bus trip depends on the running speed which is in turn affected by bus lane capacity and ridership. Within the proposed bimodal framework, the steady-state equilibrium traffic characteristics and the optimal bus fare and service frequency are analytically derived. The counter-intuitive properties of traffic condition, modal split, and behavior of bus operator in the hypercongestion are identified. To understand the interaction between the transport authority (for system benefit maximization) and the bus operator (for its own benefit maximization), we examine how the bus operator responds to space changes and how the system benefit is influenced with the road space allocation. With responsive bus service, the condition, under which expanding bus lane capacity is beneficial to the system as a whole, has been analytically established. Then the model is applied to the dynamic framework where the space allocation changes with varying demand and demand-responsive bus service. We compare the optimal bus services under different economic objectives, evaluate the system performance of the bimodal network, and explore the dynamic space allocation strategy for the sake of social welfare maximization.     

Planning and control of paratransit services in Hong Kong

As paratransit services, Hong Kong's taxis and public light buses (PLB) carried some 30% of the 9.7 million daily public transport boardings in Hong Kong in 1988. Most of the vehicles are individually owned, and services are operated as commercially viable concerns. While operators have a high degree of operational flexibility, taxis and PLBs are closely regulated by the Government. The fleet sizes are controlled by licensing. There is a system of zoning for taxis, and operational prohibitions and restrictions for PLBs. Over the years, Hong Kong has developed some practicable means of operational control on taxis and PLBs. It has been 20 years since PLBs were legalized in 1969. The transition experienced by this mode, from no control to regulated operations, signifies a major step forward from the point of view of transport administration. The Government's participation in the planning for PLB services has guided the development of this mode. In this paper, the planning and control mechanisms for Hong Kong's paratransit modes are introduced. Identified deficiencies are also discussed.     

Preferences of travellers for using automated vehicles as last mile public transport of multimodal train trips

In the recent years many developments took place regarding automated vehicles (AVs) technology. It is however unknown to which extent the share of the existing transport modes will change as result of AVs introduction as another public transport option. This study is the first where detailed traveller preferences for AVs are explored and compared to existing modes. Its main objective is to position AVs in the transportation market and understand the sensitivity of travellers towards some of their attributes, focusing particularly on the use of these vehicles as egress mode of train trips. Because fully-automated vehicles are not yet a reality and they entail a potentially high disruptive way on how we use automobiles today, we apply a stated preference experiment where the role of attitudes in perceiving the utility of AVs is particularly explored in addition to the classical instrumental variables and several socio-economic variables. The estimated discrete choice model shows that first class train travellers on average prefer the use of AVs as egress mode, compared to the use of bicycle or bus/tram/metro as egress. We therefore conclude that AVs as last mile transport between the train station and the final destination have most potential for first class train travellers. Results show that in-vehicle time in AVs is experienced more negatively than in-vehicle time in manually driven cars. This suggests that travellers do not perceive the theoretical advantage of being able to perform other tasks during the trip in an automated vehicle, at least not yet. Results also show that travellers’ attitudes regarding trust and sustainability of AVs are playing an important role in AVs attractiveness, which leads to uncertainty on how people will react when AVs are introduced in practice. We therefore state the importance of paying sufficient attention to these psychological factors, next to classic instrumental attributes like travel time and costs, before and during the implementation process of AVs as a public transport alternative. We recommend the extension of this research to revealed preference studies, thereby using the results of field studies.     

The power of reforming streets to boost access for human-scaled vehicles

This commentary argues for strategies to rapidly increase access by small, human-scaled modes in cities through changes to street designs. Such rapid transformations are necessary as part of responses to critical environmental, economic and public health challenges cities face. We explain that even though coordinated transport and land use planning is desirable, the built environment is mature and slow to change, while streets can and have changed in character and use frequently. This suggests that access to employment, amenities and services should be dramatically increased through reoriented street space toward human-scaled transport modes which will improve safety, reduce pollution, and save households and governments money. We then articulate the prospects of a new generation of accessibility research based on network evolution.     

Do supra-modal traveller types exist? A travel behaviour market segmentation using Goal framing theory

Travel behaviour market segmentations have become a popular method of identifying different types of car users, bicyclists or public transport users. However, while previous studies have looked at different types of users within single modes, such as the car, little research has explored the existence of traveller types transcending modes. The study presented here is an extension of an earlier segmentation study that distinguished travellers based on their individual preferences, yet did so independent of their current mode choice. The data came from a travel survey at a middle-sized UK university and were analysed using a combination of hierarchical and iterative partitioning methods. Crucially, however, the current study uses a different theoretical framework to previous segmentation research—goal framing theory—which may more adequately explain the findings than models used in the past such as the theory of planned behaviour. The findings supported earlier work, suggesting the presence of seemingly stable traveller types that cut across modes and can be distinguished based on gain, hedonic and normative goals. This has important implications for policies aimed at encouraging mode change which may have been too preoccupied with changing people’s attitudes rather than paying attention to people’s underlying travel preferences.

     

Optimization of transport investment and pricing policies: the role of transport pricing in network design

This paper investigates the role of transport pricing in network design and describes two facts about flow pattern in a transportation system. The first, illustrated by an example of Braess paradox, is that adding a new link to the network does not necessarily minimize the total travel time. The second is that introducing of appropriate toll pricing may reduce not only the total network time but also the travel time for each individual traveller. It follows with the investigations of different system objectives and different pricing policies (only toll pricing and distance‐based pricing are considered), and shows how they affect the system performance and flow pattern. Lastly, a systematic optimization process is proposed for integrated planning of transport network and pricing policies.     

Transportation and income inequality in China: 1978–2007

This paper mainly studies how various types of transportation modes are associated with income inequality in China for the years between 1978 and 2007. Gini coefficients are used to measure the income inequality nationwide, and within urban and rural areas of China. Factors other than transportation are also considered in the regression model, including a few demographic variables and major economic indicators. We contribute to the literature by examining the income redistributive effects of transport infrastructure and services, and providing transport planning and policy guidance which may alter the orientation of public policy and help alleviate the growing social and economic imbalance in China.     

Managing with declining resources

Urban public transport has had broad political appeal and escalating financial support since the late 1960s. The preference has been for public ownership and operation of services with only limited private sector involvement in the provision of services in a highly regulated environment. The financial standing of public transport coupled with the likelihood of a sustained period of fiscal restraint, perhaps even a decline in available resources, has created an imperative for change. This paper argues that broad‐based acknowledgment of the financial realities, clear definition of quantifiable objectives and increased authority and control for public transport management is required if public transport agencies are to meet the challenge. A new balance between service, ridership and revenue is required. Managing with declining resources will require a financial planning approach, separation of policy and planning from operations, removal of restrictions on user choice and operator competition and increased involvement of the private sector. Substantial changes in internal organization, procedures and structures and a cost‐effectiveness orientation will be necessary.     

Explaining public transport information use when a car is available: attitude theory empirically investigated

Despite recent investments in and growing availability of various public transport information services, levels of apparent non-use (of particular information services) across the population remain high. Policymakers and information service providers could benefit from a better understanding of factors affecting information use. The goal of this paper is to provide more insight into the (non-)use of public transport information by applying attitude theory. A postal survey was sent to a random sample of 10,000 households in Bristol and Manchester, UK. The response rate was 13%. Respondents were questioned about an uncertain journey they were going to make. Structural equation modelling has been used to investigate interdependencies among the factors studied. The results show that the desire to consult public transport information for an uncertain journey is affected by attitudes, subjective norms, and past behaviour. These social-psychological factors are in turn affected by constraints such as travel behaviour and trip context. Crucially in terms of addressing issues of non-use of information it is found that consulting information is influenced by propensity to consider using public transport rather than vice versa as has hitherto been implicitly assumed by many involved in the provision of transport and information services.     

Development and Deployment of Public Transport Policy and Planning in Taiwan

Over the past decade, the escalating roadway congestion and environmental deterioration due to heavy use of private vehicles have provoked the Taiwan government to realize the importance of public transport systems. Under the “carrot-and-stick” rationales, the government has formulated public transport policies and exercised a series of related initiatives by providing sufficient and higher quality of public transport services so as to attract more private vehicle users. In this paper, the planning philosophy and policy formulation of Taiwan’s public transport development are highlighted. The most important initiatives, including the Five-year Enhancement of Mass Transportation Program and the upgrading public transport schemes in the National Development Plan are examined. Based on previous experience and lessons, we point out the most challenging issues that the government will encounter. Suggestions for the future of public transport planning are also addressed.     

A monopolistic market for advanced traveller information systems and road use efficiency

Advanced traveller information systems (ATIS) are likely to exhibit significant economies of scale in production and operation. Private provision would therefore typically occur under considerable market power. An important policy question is whether the resulting distortions would aggravate or reduce distortions in the transport market itself, notably external effects such as congestion. We consider such questions by presenting an integrated model that captures the interactions between a congested transport market and a monopolistic market for advanced traveller information systems (ATIS). Three market failures operate simultaneously: congestion on the road, a declining average benefit of information when information penetration rises, and monopolistic pricing by the provider of information. Some key results are as follows. Monopoly information pricing appears not to be the most attractive option from a system efficiency viewpoint. A subsidy in the information market can help realise a second-best optimum of road use. Relatively low uncertainty on the road and high information costs limit the monopolist’s profit on the information market, as well as relative system efficiency. While relatively inelastic demand for mobility, counter intuitively, negatively affects the monopolist’s profit, the relative social benefits from private information peak at intermediate demand elasticities.     

Urban public transport in Europe: Technology diffusion and market organisation

Technological change and incremental technology, at various levels, are believed to have played an important role in the success of urban public transport in Europe. In this paper, a historical overview of the evolution of different transport modes across different European cities is presented. Our major concern is with the processes of diffusion of urban transport modes in European cities and, in particular, with the factors, mainly of an economic nature, that may explain their rates of adoption across Europe. Among these factors, special attention is given to the role played by the dimension and organisation of public transport markets in the rates of adoption of different public transport modes. The main conclusion of the paper is that the success of the introduction of a new transport mode appeared to be mainly related to its ability to provide cheaper and more reliable transport services compared with previous transport modes, and that, in the case of the electric tram, this was achieved by transforming of the structure of the market relating to this urban transport mode into monopolies.     

Traveler expectations and willingness-to-pay for Web-enabled public transport information services

Web-enabled public transport (PT) information systems that combine information on different PT modes, different PT companies and different geographical regions, can be built to improve the accessibility of public transportation. As the potential list of information aspects that can be included in such systems is long, it is interesting to examine the relative importance of different information aspects. This study reports the relative importance travelers attach to a range of information aspects. In addition, the willingness to pay for this information was examined by conducting a stated choice experiment, in which price was traded off against groupings of information aspects. The results of the study indicate that even though public transport travel information is highly price sensitive, travelers are willing to pay for it if the information systems provide additional functionality such as real-time information and, to a lesser extent, additional trip planning options.     

The rationality of transport investment packages

Investment packages, involving several modes, emerge as a widely used element in urban transport policies. Package policies entail some specific possibilities and traps in the planning and decision-making processes. To assess these properties, the concepts of instrumental and communicative rationality are applied. These rationality concepts serve to structure the pro and con arguments concerning four crucial considerations in package planning: The use of formal impact assessment methods, the overall size and changeability of the investment packages, the share of road vs green modes investments, and the sequence of implementation. These issues are investigated by drawing on experience from transport investment packages in six Norwegian cities.     

Simulating Demand-responsive Transportation: A Review of Agent-based Approaches

Abstract

In light of the need to make better use of existing transport infrastructure, demand-responsive transportation (DRT) systems are gaining traction internationally. However, many systems fail due to poor implementation, planning, and marketing. Being able to realistically simulate a system to evaluate its viability before implementation is important. This review investigates the application of agent-based simulation for studying DRT. We identify that existing simulations are strongly focused on the optimisation of trips, usually in favour of the operator, and rarely consider individual preferences and needs. Agent-based simulations, however, permit incorporation of the latter, as well as capture the interactions between operators and customers. Several areas of future research are identified in order to unify future research efforts.