Flexible Transport Services Research Articles

A multi-task deep learning framework for forecasting sparse demand of demand responsive transit

Demand Responsive Transport (DRT) is a flexible transportation service that adjusts its routes and schedules in real time based on user requests. Real-time demand forecasting has become a timely issue since the resolution of transportation planning has increased to provide flexible services to users. Although many previous studies have been conducted to design the demand forecasting model using the mobility service historical data, there are more considerations when predicting real-time demand for on-demand mobility services. Therefore, this study aims to develop a demand forecasting model for DRT services addressing two issues. First, repeated calls for service and abandoned requests are converted into the unit of demand to capture served and potential demand. Second, given the sparsity of DRT historical data, a multi-task deep learning model is proposed to predict both the probability and volume of demand simultaneously to mitigate the data sparsity problem. A zero-inflated loss function was introduced to consider the skewed demand distribution. To attain our goals, the historical dataset of the I-MOD service trial in Yeongjongdo, Inchon, Korea was used. The performance of the proposed model is compared against several baseline models, demonstrating its superiority in forecasting demand for mobility services. The results show that a multi-task structure can alleviate the data sparsity problem by excluding where demand is not generated from the forecasting problem. The proposed models can provide insights into real-time demand forecasting with sparse demand.

Factors influencing the patronage of flexible transport in urban and rural areas. A case study in NSW, Australia

Since 1990, gradual changes have been observed in the implementation of flexible transport service (FTS) schemes. A growing body of evidence suggests FTS are highly supportive for specific groups, like people with disabilities and the socially disadvantaged. Although this is more evident in rural and regional areas where there may be no fixed public transport routes, some urban FTS schemes have proven effective. However, little empirical research has focused on exploring the factors influencing patronage of FTS in urban and rural areas. This study aims to understand the relationships between patronage and the user's characteristics in New South Wales, Australia, by associating spatial datasets and employing statistical modelling to compare the experience in urban and rural contexts. Results show that users' characteristics of flexible transport are contrastingly different in urban and rural areas; and that this method represents an effective tool to capture the economic and social benefits for FTS users. This study posits that tangible evidence is not enough to evaluate and assess FTS schemes and points out that a careful understanding of the FTS user's benefits is needed to assess the effectiveness of FTS. These findings contribute to a better understanding of flexible transport implementation and provide evidence for FTS scheme proponents and transport funders.

Agent-based models for simulating e-scooter sharing services: A review and a qualitative assessment

E-scooter sharing services have grown exponentially in many cities of the world within the last 10 years, mainly with the goal to serve first/last mile trips. Compared to other shared mobility modes (e.g., autonomous buses and electric taxis), for which Agent-based Models (ABMs) have been applied in many cases, just a few studies attempted to simulate e-scooter trips. This study aims to bridge the gap between ABMs and e-scooter sharing services by reviewing the existing ABMs and conducting a qualitative assessment. Initially, existing ABMs are described based on ten descriptors. To test suitability of each model for simulating e-scooter sharing services, we developed an evaluation checklist based on empirical findings. The ten criteria refer to the capabilities of each model to (a) adjust in new challenges via an open-source code, (b) model shared mobility modes, (c) perform large scale simulation, (d) describe spatiotemporal variation of demand, (e) simulate bicycle, (f) pedestrian, and (g) mixed traffic (h) consider socio-demographic characteristics, (i) integrate new choice models, and (j) model multimodal trips. Our results reveal the advantages and disadvantages of each model in simulating flexible transport modes and services. We end up with a dilemma or a scalability problem: to model e-scooter riding behavior in link level or e-scooter services in network level. It is concluded that the dual behavior of e-scooter users (pedestrian or vehicle) poses new challenges that can be met through the development of new extensions or hybrid simulation models.

Ligurian Internal Areas and Demand Responsive Transport: an innovative approach to tackle social exclusion and to re-design sustainable accessibility

Making public transport more flexible, sustainable and efficient has been one the main goals of the last decades for Public Administrations in order to improve urban performances in mobility sector, that is responsible for a big share of pollutant emissions and deeply affects quality life level. Anyway, recently, attention grew on the fact that this topic does not belong to urban areas only and needs tailored measures to be effective: accessibility for peripherical and scarcely populated areas represents the pre-requisite of citizenship rights itself. Basic services (health, education above all) are getting more and more concentrated in order to reduce costs and this means that non-urban residents have to make long trips to reach them. Public Transport itself has become no longer sustainable in these territories because of the small population and low-density levels of transport demand (the so-called “low-demand areas”). That is the reason why flexible and customizable solutions (Demand Responsive Transport-DRT, for instance) could meet the needs of these remote inhabitants, thus improving social inclusion and being the first step to more complex regeneration processes. Italian National Internal Areas Strategy (SNAI) focuses on mobility actions, too. Many flexible transport services have been proposed in order to balance accessibility rights of local residents and economical and environmental sustainability of the service itself. This paper presents the Ligurian Internal Areas experiences (and specifically Antola-Tigullio strategy), where DRT services implementation is currently taking place to tackle marginalization process: referring to these areas non-traditional transport services allow to cover larger areas and longer parts of the day, without adding new costs (service is active only when users need it), thus developing a new mobility scheme.

Boda bodas: The new form of adventure tourist transportation in Uganda

Abstract Tourist transportation at local destinations has transformed, with the use of motorcycles (Boda-bodas) becoming popular, especially for adventurous tourists. In Uganda, motorcycle taxis, also known as Boda-bodas are now popular as both a mode of tourist mobility and a tourist product. This paper makes one of the first attempts to integrate the Ugandan Boda-boda tourist transport into the global tourism academic debate. Results show a surge in the number of private operators who are providing affordable and flexible transport services to both locals and tourists. As such, more Boda-boda riders are joining government licensed associations/orgamisations for authentication. Despite its growing popularity, Boda-boda transport is still associated with challenges of road accidents and loss of clients’ property mainly due to poor enforcement and observance of road traffic and safety regulations coupled with the current poor state of the roads. Going forward, there is an urgent need to institutionalize Boda-boda tourist transport to ensure safety and security of tourists and their property as well as other road users.

The Potential Role of Flexible Transport Services in Enhancing Rural Public Transport Provision

This paper explores the existing context of public transport provision in rural and remote areas illustrated with experience from Scotland. A critical review of existing Flexible Transport Services (FTS) in rural areas is provided and illustrated with selected case studies, with the objective of identifying the extent to which FTS can enhance the public transport offer. Findings confirm that FTS offers considerable potential to contribute to and support the public transport system in rural areas; however, the paper also identifies the many challenges in successful development or enhancement of FTS in rural areas.

Shippers’ willingness to use flexible transportation services

Factors driving the choice of shipper firms for services of logistics service providers have long been recognized in the freight transportation literature. However, the willingness among shippers to choose flexible transportation services, where the service package can be adapted during planning and execution, has received less attention. In particular, little is known about the contextual circumstances under which shippers would be inclined to select such flexible transportation service. In this study, experimental scenarios and discrete choice modeling are used to investigate the willingness among shippers to use flexible transportation services. We estimate multinomial logit, mixed logit, and latent class models for a sample of nearly 200 global shipper firms and calculate willingness-to-pay measures for flexibility. The findings indicate that flexible services are essential in demand-volatile markets. Since logistics services may provide external flexibility for shipper firms, we also study which related internal flexibilities in supply chains drive these choices. In particular, our findings show that it is mainly the volume flexibility of shippers that mediates the choice of flexible transportation services.

Evaluation methods and governance practices of new flexible passenger transport projects

The emergence of new flexible passenger transport services enabled by technological advancements can have substantial impacts on efficiency and sustainability of public transport systems. Socio-economic appraisal methods of transport investments have developed during last decades, and especially CBA is proven to provide robust method for ranking alternative large conventional transport investments such as rail and road projects. However, there is much more uncertainty with potential impacts of new flexible passenger transport serves such as the automated demand responsive transport services, which can be seen as disruptive technologies on the transport markets. For addressing this uncertainty, we studied governance practices for using CBA and other economic appraisal methods in public decision making in the European Union with a special focus on Germany. We identified and analysed the most uncertain and challenging impacts of the new flexible transport services, which require better consideration in current evaluation methods and practices. The results point out challenges and opportunities for reaching the gap between current appraisal practices and the latest knowledge on the potential impacts of new flexible passenger transport services.

Addressing the public transport ridership/coverage dilemma in small cities: A spatial approach

This paper presents a spatial approach to support the design of new on-demand flexible transport services in urban areas, characterized by inefficient public transport and modal imbalance in favour of private cars. These services, enabled by new technologies and inspired by the shared mobility paradigm, can complement and improve conventional public transport and reduce car use. The methodology was applied to Acireale, a small town in Southern Italy. A redesign of the existing bus network and its integration with a flexible service was formulated. A scenario analysis was carried out by the evaluation of a simple accessibility measure; the computation of the Gini coefficient was performed to measure the social equity of different scenarios. Results show an increase in equity with a lower coverage of traditional lines and the introduction of the on-demand service. This approach based on easy-to-understand indicators can help the strategic planning of such services, which have the potential to find a trade-off between ridership and coverage as both desirable and conflicting goals in public transport planning.

Mobility as a service (MaaS): Charting a future context

Abstract This overview article proposes a revised approach to improve the urban realm, against the backdrop of new models for delivering transport services as digitalisation, collaborative consumption and autonomous technologies take hold. We propose the concept of modal efficiency illustrated through a conceptual framework situating both existing and emerging modes of transport around spatial and temporal dimensions. This framework helps us evaluate how the push towards smaller and more flexible transport services in questionable settings can have significant and adverse effects on road capacity, increasing congestion and in the longer term impacting urban form. We propose linking urban land use characteristics to travel price and modal efficiency to improve the broader transport system and guide the sustainable development of our cities. Mobility as a service (MaaS) based on shared mobility and modal integration constitutes a major opportunity to deliver on these ideals, if organised appropriately. Widely diverging service delivery models for MaaS are introduced, including commercially-motivated models (which may exacerbate efficiency issues), and systems which incorporate an institutional overlay. We propose consideration of a government-contracted model for MaaS, where road pricing is incorporated as an input into package price, defined by time of day, geography and modal efficiency. In amidst the hype of new mobility technologies and services, a critical assessment of the realm of possibilities can better inform government policy and ensure that digital disruption occurs to our advantage.

Core-Selecting Auctions for Autonomous Vehicle Public Transportation System

With the technological advancements, the autonomous vehicle (AV) is expected to play an active role in the future transportation system. An AV-based public transportation system was recently proposed to unleash the full capability of AVs to provide effective and flexible transportation services. It establishes a new public transportation market that can accommodate multiple vehicle operators. Such multi-tenant system encourages market competition for better quality of service. The pricing process in the original proposal was designed based on the Vickrey–Clarke–Groves mechanism, but it is vulnerable to the problems of payoff reduction and shill-bidding. In this paper, we reinvestigate the pricing process to address these vulnerabilities. We formulate it as core-selecting reverse combinatorial auctions and investigate the properties of the “core.” We establish a core-selecting mechanism that can maximize customer's utility and prevent shill-bidding. We analyze the theoretical properties of the formulated auctions and the core-selecting mechanism. We verify the results with extensive simulations. The simulation results show that the core-selecting mechanism can result in lower service charge, and suppress untruthfulness, shill-bidding, and coalition formation. It can produce auction results in linear computation time, making it scalable and practical.

Planning of Flexible Transport Services for Rural Area Considering Operation Cost

Planning of Flexible Transport Services for Rural Area Considering Operation Cost

Factors Preventing the Use of Alternative Transport Modes to the Car in Later Life

Recent research related to transport gerontology argues that the autonomy, flexibility and independence provided by the car are fundamental in fulfilling travel needs in later life. Statistics show that in the western world the car is the most used mode of travel among the older population. Despite the importance of promoting transport policies to incentivize people to switch to more sustainable forms of transportation, alternatives to the car are still underused by older people. The aim of this scoping review is to analyze the transport barriers affecting the use of alternative modes to the car in later life. The paper investigates how issues related to personal security, health impairments, service provision, affordability, comfort, attitude, built environment, information and awareness of all transport modes influence modal choice. The analysis of the literature shows that despite the benefits provided by public transport, flexible transport services, taxis, walking and cycling, there are still several factors that negatively affect the use of these modes. The paper concludes by reflecting on potential solutions that might help to create a transport system less reliant on the car and which is able to meet the mobility needs of the older population.

A Gamified Flexible Transportation Service for On-Demand Public Transport

Present public transport services still suffer from issues such as time deviations from the static timetable, overcrowded buses, increased on board time, and long wait at bus stops. This work studies the experimental implementation of an on-demand public bus transportation service in Trikala, a medium-sized Greek city. With a view to optimize the service from both the operator’s and the citizens’ point of view, this paper presents an insertion heuristic solving the static multivehicle dial-a-ride problem with time windows and a fixed fleet of vehicles. Since viability of such a service depends on its ability of involving a significant number of users and getting reliable information, we tested a gamification layer, aimed at motivating public transport users to participate and behave correctly with the system. We present and discuss a novel pervasive computing architecture and various types of serious games designed to achieve these goals. We finally report early usability test results and some simulation-based indications on the design of city-scale deployable serious games to enhance public transport-based mobility.

A tool to aid redesign of flexible transport services to increase efficiency in rural transport service provision

ABSTRACTRural areas generally have lower and more dispersed demands for travel which cannot sustain conventional public transport services and consequently have a greater number of flexible and demand responsive transport services operating. These services usually operate on a stand-alone basis, are often subsidized and are typically only accessible by certain passenger types or for specific trip purposes. This generally results in uncoordinated and inefficient transport provision overall. The Flexible integrated transport services (FITS) system featured in this paper has been designed to address this problem. FITS can be used as a planning tool to assess potential benefits from relaxing operating constraints (e.g., a service's operating boundaries), which can potentially suggest service redesign. It also includes the capacity to assign subsidy payments on a trip by trip basis to increase cost efficiency whilst meeting a greater proportion of transport needs. The case study in the paper focusses on transport to health in the Aberdeenshire and Morayshire areas of Scotland in the UK. Despite flexible transport operators receiving public funds to meet passenger needs, this is currently being supplemented by public bodies paying large amounts in taxi fares in instances where there is a statutory obligation to provide travel but where no other suitable transport service exists. The results demonstrate the potential substantial savings which could be realized by allowing transport operators to redesign their services by relaxing constraints and by the reassignment of subsidies: resulting in more passenger demands being met and a reduction in public spending on taxi fares.

Enhancing flexible transport services with demand-anticipatory insertion heuristics

Developments in vehicle automation and the shared economy call for new developments in routing flexible transport services. We propose a new type of insertion algorithm: an online dynamic insertion algorithm with demand forecasts. The performance of this algorithm is tested in a simulation model for a case study network in the Netherlands. When combining the new insertion algorithm with empty vehicle rerouting, 98% of passenger rejections are eliminated and travel and waiting times are reduced by up to 10 and 46% respectively, compared to traditional insertion algorithms. A sensitivity analysis tested performance robustness to variations in operational and demand conditions.

Policy lessons from the flexible transport service pilot Kutsuplus in the Helsinki Capital Region

An increasing number of flexible micro transport services (FMTS) is an emerging response to tackling sustainability issues of urban mobility. Meeting the challenges of changing user requirements and difficulty in accomplishing modal shift policy goals, FMTS can respond, owing to advances in technological solutions. However, these novel services are still facing a range of barriers, including institutional, cultural, and economic hindrances. Moreover, there is a general lack of knowledgebase related to FMTS deployment in urban areas. Consequently, the objective of this article is to present policy and planning lessons on urban FMTS. The lessons are derived from a unique FMTS pilot in the Helsinki Capital Region. This FMTS pilot, called Kutsuplus, was operational from October 2012 to December 2015. The study includes an analysis of operational data, as well as policy-making processes, including expert interviews. The key findings provide a range of guidelines and lessons for future urban FMTS. The first set of transferable guidelines relates to the Kutsuplus setup and organization. The second set concerns fare determination and financing. The third set involves decision-making processes and stakeholder involvement. In addition, a range of other lessons are highlighted for future pilots. The results point towards the recommendation to look beyond long-term financial sustainability by taking into account a range of interdependent factors, starting from the initial planning stage.

An agent-based day-to-day adjustment process for modeling ‘Mobility as a Service’ with a two-sided flexible transport market

Due to advances in communications technologies and social networks, flexible mobility systems such as taxi, carpool and demand responsive transit have gained interest among practitioners and researchers as a solution to address such problems as the ``first/last mile problem". While recent research has modeled these systems using agent-based stochastic day-to-day processes, they assume only traveler adjustment under a one-sided market setting. What if such systems are naturally ``two-sided markets" like Uber or AirBnB?In this study, we explore flexible transport services in the framework of two-sided markets, and extend an earlier day-to-day adjustment process to include day-to-day adjustment of the service operator(s) as the seller and the built environment as the platform of a two-sided market. We use the Ramsey pricing criterion for social optimum to show that a perfectly matched state from a day-to-day process is equivalent to a social optimum. A case study using real data from Oakville, Ontario, as a first/last mile problem example demonstrates the sensitivity of the day-to-day model to operating policies. Computational experiments confirm the existence of locally stable states. More importantly, the experiments show the existence of thresholds from which network externalities cause two-sided and one-sided market equilibria to diverge.

Performance assessment of fixed and flexible public transport in a multi agent simulation framework

The emergence of innovative mobility solutions that offer flexible transport services, is changing the way urban public transport systems will be designed. Such mobility solutions offer on demand transport services and hence can solve the problems inherent with traditional line based and schedule based public transport systems. It is essential to understand the dynamics of this new demand-supply market with co-existing and competing fixed and flexible public transport. However, the performance of the system comprising of users and transit services and the factors influencing them, have received limited attention in literature. In this paper a model is developed to analyse the system performance when the modes of fixed public transport and flexible public transport operate in competition. The model is implemented in the multi-agent simulation framework MATSim with dynamic assignment in which the users optimise their travel plan through iterative learning from the service experienced and altering their travel plan. The scenarios in which the flexible public transport offer private and shared services are considered. The system performance is analysed for varying fleet size of flexible public transport and ratio of cost of flexible to fixed public transport.

Public Vehicles for Future Urban Transportation

This paper advocates a new paradigm of transportation systems for future smart cities, namely, public vehicles (PVs), that provides dynamic ridesharing trips at requests. Passengers will enjoy more convenient and flexible transportation services with much less expense. In the PV system, both the number of vehicles and required parking spaces will be significantly reduced. There will be less traffic congestion, less energy consumption, and less pollution. In this paper, the concept, method, and algorithm for the PV system are described. The key issue of effectively implementing the PV system is to design efficient planning and scheduling algorithms. The PV-path problem is formulated, which is NP-complete. Then, a practical approach is proposed, which can serve people anywhere and anytime. The simulation results show that, to achieve the same performance (e.g., total time, waiting time, and travel time), the number of vehicles in the PV system can be reduced by around 90% and 57% compared with the conventional vehicle system and Uber Pool, respectively, and the total traveling distance can be reduced by 34% and 14%.