Travel Time Savings Research Articles

Joint optimization of metro train timetable and stopping plan for the first service period: An integrated energy-efficient and time-saving model

This paper addresses the energy conservation challenge in metro systems during the first service period, characterized by large train headways and low passenger demands. A novel train timetabling method incorporating an express-local mode is proposed to maximize the overlap time between accelerating and braking trains, thereby facilitating the utilization of regenerative braking energy (RBE). Local and express trains depart alternately, with skip-stop strategies implemented for express trains. Considering the interests of operator and passengers for energy and travel time savings, a bi-objective model is proposed to jointly optimize train timetable and stopping plan. NSGA-II is applied to solve the model and obtain Pareto optimal solutions. Numerical experiments based on Ningbo Metro Line 1 data validate the effectiveness of proposed methods, showcasing significant enhancement in RBE utilization and notable reduction in passenger travel time. The proposed express-local mode establishes stable tracking relationships within train pairs, ensuring effective RBE utilization. Comparative analyses reveal that deadheading is more effective than flexible skip-stop for energy-efficient and time-saving metro operations.

A framework for modal split and implications on transport growth and travel time savings

Mobility is one of the most debated issues in the current discussion on transport policies and the climate change. Related indicators are the modal split, transport growth and travel time savings, used for travel behaviour evaluations. In official transport statistics, the modal split is generally used in two ways, according to the number of modal trips and to the modal trip length. Although they are usually used separately, we will show that they are directly connected, where the latter is a weighted version of the former. The introduction of the reference units of “person” and “day” overcomes the limitations of a trip-based definition and extends the ansatz to a mobility-based methodology, where all modal combinations can be considered. Empirical data analysis shows, that transport growth is founded on the increase of individual motorised transport at the disadvantage of pedestrians, whereas other modes remain fairly stable. Daily travel time generally increases especially with individual motorised transport in comparison to non-motorised modes, which shows an inconsistency, for example, for some assumptions or approaches of travel time savings. The proposed methodology does not require any prior assumptions and provides therefore a simple and general applicability. The data analysis is based on national travel survey data from Germany, Switzerland, UK and USA from the 1970-ies up to 2018. One main result of the paper is a frame of reference for the relativity of mobility behaviour, which consistently connects these mobility indicators.

High-speed railway in developing countries: mind the gap -lessons from Morocco-

ABSTRACT Conducted prior to the launch of the High-Speed Railway (HSR) in Morocco, this study aims to be the first research to assess the HSR project through the estimation of the value of travel time savings. We focused on inter-urban routes to assess the HSR project impact. We conducted a Discrete Choice Experiment in the cities impacted (directly or indirectly) by the HSR project, which are Tangier, Kenitra, Rabat, Casablanca and Marrakesh. Our results show that at the sample average points of each mode of transport, the values of travel time savings are approximately 94MAD/h for car users, 27MAD/h for train users and 25MAD/h for bus users. We performed a simulation for the Tangier-Casablanca route and obtained satisfactory results (93MAD/h, 26MAD/h and 24MAD/h, for private car, train, and bus journeys respectively). Finally, our results show that the pricing strategies of the national railway operator (Office National des Chemins de Fer) present a potential risk of eviction, which could counterbalance the positive impact of the time savings.

Access-based cost-benefit analysis

Current methods of cost-benefit analysis (CBA) for transport investments rely on travel-time savings for potential users. This approach presents a consistent and significant historical trend of forecast inaccuracy, and thus has been questioned and criticized. Access, or the ease of reaching valued destinations, can be used as an alternative. Access features a strong correlation with land value which can be measured through hedonic analysis, and subsequently, access gains offered by a transport initiative can be monetised via property uplift. We test this hypothesis and evaluate Sydney's South West Metro Link (SWML).We first develop linear and semi-log ordinary least square hedonic pricing models for house sales in the Sydney region. The models are set up with structural and neighbourhood attributes in addition to access measures, and result in a statistically significant fit.Next, we model changes to job access induced by the SWML. Benefits are then quantified by land value uplift and are estimated at $1.87 Billion in 2031 and between $1.53–$3.08 Billion in 2061, which reflect base and transit-oriented development (TOD) scenarios. The project is thus feasible should certain land use and economic conditions be met, including TOD to occur about station localities by 2061 and if project costs are minimal. Although limitations are noted, access-based CBA exhibits significant promise as an alternative approach to appraisal and has direct application in value capture strategy.

Transportation Mode Choice and Sustainability

This study conducted in Bandung Regency delves into the factors influencing the choice of transportation modes for tourists and provides practical insights. Specifically, the research examines the influence of park-and-ride security, travel time savings, and travel costs on the selection of private vehicles and shuttle buses. The findings emphasize the importance of sustainable transportation facilities and efficient public transport services, offering a practical roadmap for addressing transportation needs for tourists in Bandung Regency. With a focus on the park-and-ride concept, this research identifies and analyzes the factors influencing mode choice between private vehicles and public transportation. The study was conducted in Ciwidey, a natural tourism area in Bandung Regency, which offers diverse attractions such as nature-based tourism, ancient sites, culinary experiences, and water tourism. The findings of this research aim to contribute to the improvement of sustainable transportation and mobility choices for tourists while alleviating traffic congestion and environmental impact in Bandung Regency's tourism areas.

E-learning Method and University Life of Married Female Students in Patriarchal Social Structure in Sociological Perspective

Education is a process and means of human empowerment and social transformation. There are both formal and informal practices in educational processes. University is a unit of the formal education system that provides specific knowledge and skills in a universal context. Face-to-face teaching is traditionally practiced as the teaching pedagogy in university education in Nepal. This paper analyzes the challenges and opportunities of e-learning for married female students within the university context under the patriarchal social structure. Married female students’ in-depth interviews based on the challenges and opportunities they faced in the e-learning system in university education have prepared the cases through their narratives as the primary date of the research. The cases have been collected by purposive sampling through the university level of students. The content analysis method has analyzed both primary and secondary data types. Married female students have been found to suffer from problems with individual devices, financial problems, computer literacy, regularity of electricity, and poor internet quality. Similarly, they have to face house-loaded problems during class time. They have the opportunity to manage household activities and adapt to new technology in learning, saving travel time and cost under the e-learning system of university life. The theoretical explanation of patriarchy only gets partially analog except for the partial application of its assumptions in the e-learning system, mainly for the married female students of the university.

Assessing automated air-taxis for urban mobility

This paper explores the feasibility and potential implications of automated air-taxis as a new mode of urban transport. By applying flight simulation and operations research, we investigate different questions regarding travel time, travel costs, and transport sustainability. As practical application, we consider the transportation service between the city and the airport, as well as on-demand air-taxi services within the city of Vienna. We compare the air-taxis with gasoline taxis and e-taxis, as they serve analogous transportation needs and cater to a similar clientele. In our effort to assess the feasibility of air-taxis, we aim to answer crucial questions that will influence the future of urban transportation. Our study examines how efficient air-taxis are in reducing travel time and explores their cost dynamics, addressing the affordability for passengers and their value of travel time savings. Additionally, we investigate their environmental impact by looking into energy consumption and CO2 emissions. Through a rigorous analysis of empirical data and simulation outcomes, we aim to provide a comprehensive perspective that informs policy decisions and guides the evolution of urban transportation networks in the years to come.

Strategic integration of vertiport planning in multimodal transportation for urban air mobility: A case study in Beijing, China

In pursuit of strategic sustainable development goals, this study seeks to analyze the spatial placement of vertiports for urban air mobility, positioning them as integral components within the multimodal transportation system. We propose an iterative weighted k-means clustering method that incorporates the value of travel time of different transportation modes to identify potential vertiport locations. A multi-objective optimization model that maximizes total air taxi ridership and minimizes total facility costs and travel distances to vertiports is developed considering the constraints of the distance from vertiports to existing mobility hubs. A case study is conducted using the data of Beijing city, incorporating the modes of taxis and metro. We found that 19 vertiports can guarantee a robust performance of urban air mobility service. Users of urban air mobility can benefit from substantial travel time savings of 80% (48 min on average). This study contributes to a deeper understanding of the optimal setting of urban air mobility facilities from the perspective of network synchronization, offering useful insights into policy decision-making for sustainable infrastructure planning.

Plastic Surgery Outreach Clinics Expand Access to Cleft and Craniofacial Care in Mississippi

Abstract Accessing treatment at ACPA (American Cleft Palate-Craniofacial Association)–approved centers is challenging for individuals in rural communities. This study aims to assess how pediatric plastic surgery outreach clinics impact access for patients with orofacial cleft and craniosynostosis in Mississippi. An isochrone map was used to determine mean travel times from Mississippi counties to the sole pediatric hospital and the only ACPA-approved team in the state. This analysis was done before and after the establishment of two outreach clinics to assess differences in travel times and cost of travel to specialized plastic surgery care. Two sample t-tests were used for analysis. The addition of outreach clinics in North and South Mississippi led to a significant reduction in mean travel times for patients with cleft and craniofacial diagnoses across the state's counties (1.81 hours vs 1.46 hours, P < 0.001). Noteworthy travel cost savings were observed after the introduction of outreach clinics when considering both the pandemic gas prices ($15.27 vs $9.80, P < 0.001) and post-pandemic prices ($36.52 vs $23.43, P < 0.001). The addition of outreach clinics in Mississippi has expanded access to specialized healthcare for patients with cleft and craniofacial differences resulting in reduced travel time and cost savings for these patients. Establishing specialty outreach clinics in other rural states across the United States may contribute significantly to reducing burden of care for patients with clefts and craniofacial differences. Future studies can further investigate whether the inclusion of outreach clinics improves follow-up rates and surgical outcomes for these patients.

A simulation‐based approach for optimizing the placement of dedicated lanes for autonomous vehicles in large‐scale networks

AbstractThis study introduces a framework to maximize societal benefits associated with the autonomous vehicle (AV)‐dedicated lane implementation at large‐scale transportation networks, considering the travel time savings and the required investments to prepare the infrastructure for their deployment. To this end, a bi‐level optimization problem is formulated. The upper level determines the links for dedicated lane deployment, while at the lower level, a mesoscopic traffic simulation tool is employed to enable a realistic representation of these vehicles in a mixed traffic. The problem is solved using the genetic algorithm. To further reduce the computational burden, this study adopts a clustering method based on the snake algorithm to group the candidate links and reduce the size of the solution space. The proposed framework is successfully applied to the case study of Chicago downtown network, considering various demand levels, AV market penetration rates, and implementation approaches. The results highlight the need for optimizing the placement of AV‐dedicated lanes (AVDLs) to ensure the economically beneficial adoption of this strategy across different scenarios. This study provides transportation planners with key operational insights to facilitate the effective adoption of AVDLs during the transitional phase from human‐driven vehicles to a fully AV environment.

Riding smooth: A cost-benefit assessment of surface quality on Copenhagen’s bicycle network

A growing body of research acknowledges the substantial societal benefits of improved bicycle infrastructure, with recent studies highlighting the significant impact of road surface quality on comfort, safety, and accessibility of cycling. In this paper, we present a cost-benefit assessment of improved surface quality for the City of Copenhagen. The study focuses solely on improved accessibility through higher travel speed, where two large-scale crowdsourced bicycle trajectory datasets from Copenhagen are used, along with link-specific data for the network. It is found that travel time savings that result from investments in better surface, render a benefit-cost ratio of 2 to 4 and correspond to an absolute yearly recurrent welfare gain of around 20 mill. DKK for Copenhagen. Hence, from a societal welfare perspective, careful monitoring and maintenance of surface quality is indeed a good investment. It is also demonstrated that such monitoring can be achieved in a cost-effective manner by equipping cyclists who travel in a specific area with affordable accelerometer sensors.

The value(s) of travel time savings considering in-vehicle activities.

In this note I present a theoretical formulation that incorporates the main elements behind the performance of work or leisure activities while travelling, obtaining an expanded interpretation of the values of time in terms of the role played by the values of work and leisure inside the vehicle. We conclude that the value of in-vehicle time is expected to decrease as the conditions to perform those activities inside the vehicle improve. The framework admits the possibility of negative travel time values if there are leisure activities that can only be performed while traveling and are preferred over those that can be done elsewhere.

Time use decisions in vulnerable urban communities when implementing innovative transport alternatives

Travel time savings have been the most important benefit included in transport project assessments over the last decades. However, understanding how individuals allocate this saved time after implementing transport projects is crucial, as time is a finite resource and performing more pleasant activities may impact their well-being. Large urban interventions, such as the implementation of the first cable car line in a deprived community in Bogotá (Colombia), impact how residents around the project allocate their time. We studied their time-use allocation by estimating a discrete–continuous extreme value (MDCEV) model, by combining data collected before and one year after the project implementation, to represent time-use decision changes in the study area. The results show participation and duration of different activities changed after the project implementation. The cable car increased the probability of participating in work, study, and carrying/collecting activities. It also decreased the duration of travel activities. The cable car also increased women’s time allocation to education and paid work. Overall, reduced travel time allows for more time for leisure and recreational activities. Understanding how individuals allocate their time is particularly relevant for policymakers to inform policies related to transport. This study offers valuable insights into both model development and data collection methods and the understanding of the mechanisms of time-use decisions.

Evaluation of a hybrid telehealth care pathway for patients with axial spondyloarthritis including self-sampling at home: results of a longitudinal proof-of-concept mixed-methods study (TeleSpactive)

Patients with axial spondyloarthritis (axSpA) require close monitoring to achieve the goal of sustained disease remission. Telehealth can facilitate continuous care while relieving scarce healthcare resources. In a mixed-methods proof-of-concept study, we investigated a hybrid telehealth care axSpA pathway in patients with stable disease over 6 months. Patients used a medical app to document disease activity (BASDAI and PtGA bi-weekly, flare questionnaire weekly). To enable a remote ASDAS-CRP (TELE-ASDAS-CRP), patients used a capillary self-sampling device at home. Monitoring results were discussed and a decision was reached via shared decision-making whether a pre-planned 3-month on-site appointment (T3) was necessary. Ten patients completed the study, and eight patients also completed additional telephone interviews. Questionnaire adherence was high; BASDAI (82.3%), flares (74.8%) and all patients successfully completed the TELE-ASDAS-CRP for the T3 evaluation. At T3, 9/10 patients were in remission or low disease activity and all patients declined the offer of an optional T3 on-site appointment. Patient acceptance of all study components was high with a net promoter score (NPS) of +50% (mean NPS 8.8 ± 1.5) for self-sampling, +70% (mean NPS 9.0 ± 1.6) for the electronic questionnaires and +90% for the T3 teleconsultation (mean NPS 9.7 ± 0.6). In interviews, patients reported benefits such as a better overview of their condition, ease of use of telehealth tools, greater autonomy, and, most importantly, travel time savings. To our knowledge, this is the first study to investigate a hybrid approach to follow-up axSpA patients including self-sampling. The positive results observed in this scalable proof-of-concept study warrant a larger confirmatory study.

HumanLight: Incentivizing ridesharing via human-centric deep reinforcement learning in traffic signal control

Single occupancy vehicles are the most attractive transportation alternative for many commuters, leading to increased traffic congestion and air pollution. Advancements in information technologies create opportunities for smart solutions that incentivize ridesharing and mode shift to higher occupancy vehicles (HOVs) to achieve the car lighter vision of cities. In this study, we present HumanLight, a novel decentralized adaptive traffic signal control algorithm designed to optimize people throughput at intersections. Our proposed controller is founded on reinforcement learning with the reward function embedding the transportation-inspired concept of pressure at the person-level. By rewarding HOV commuters with travel time savings for their efforts to merge into a single ride, HumanLight achieves equitable allocation of green times. Apart from adopting FRAP, a state-of-the-art (SOTA) base model, HumanLight introduces the concept of active vehicles, loosely defined as vehicles in proximity to the intersection within the action interval window. The proposed algorithm showcases significant headroom and scalability in different network configurations considering multimodal vehicle splits at various scenarios of HOV adoption. Improvements in person delays and queues range from 15% to over 55% compared to vehicle-level SOTA controllers. We quantify the impact of incorporating active vehicles in the formulation of our RL model for different network structures. HumanLight also enables regulation of the aggressiveness of the HOV prioritization. The impact of parameter setting on the generated phase profile is investigated as a key component of acyclic signal controllers affecting pedestrian waiting times. HumanLight’s scalable, decentralized design can reshape the resolution of traffic management to be more human-centric and empower policies that incentivize ridesharing and public transit systems.

Ridesourcing platforms thrive on socio-economic inequality

Limited available market share data seems to suggest that ridesourcing platforms benefit from, even thrive on, socio-economic inequality. We suspect that this is associated with high levels of socio-economic inequality allowing for cheap labour as well as increasing the share of travellers with a considerably above-average willingness to pay for travel time savings and comfort. We test the relation between inequality and system performance by means of an agent-based simulation model representing within-day and day-to-day supply-demand interaction in the ridesourcing market. The model captures travellers’ mode choice with a heterogeneous perception of relevant time components, as well as job seekers’ participation choice with heterogeneous reservation wage. Our experiments cover scenarios for the entire spectrum ranging from perfect equality to extreme inequality. For several of such scenarios, we explore alternative platform pricing strategies. Our analysis shows a strong, positive relationship between socio-economic inequality and ridesourcing market share. This is the outcome of the combination of cheap labour and time-sensitive ridesourcing users, reinforced by network effects inherent to ridesourcing markets. We find that driver earnings are minimal in urban areas with large socio-economic inequality. In such contexts, drivers are likely to face a high platform commission, and yet, fierce competition for passengers.

Introducing a Novel Framework for the Analysis and Assessment of Transport Projects in City Regions

A profound appraisal framework has been developed and refined in transport economics and planning literature for decades, mainly characterised by welfare economic theory, cost–benefit analysis, and transport demand modelling. In summary, the appraisal methodology and its applications have concentrated on single infrastructure measures, marginal impacts identified through ceteris paribus comparisons, forecasts based on trends from the past, and monetary assessments of all quantifiable impacts. However, this framework has been continuously contested in transport planning literature, for instance, for its focus on travel demand and short-term travel time savings. Therefore, we suggest a novel approach for planning and assessing transport schemes in city regions, combining accessibility analyses, quantitative target indicators, and cost-effectiveness analysis. We develop and test this approach by assessing a proposed underground rail project in the Munich city region, the U5 southeast extension. In this case, we define an accessibility target level and estimate the potential for push measures along with the U5 project. We find modest impacts on quantitative targets in the Munich city region: Even when the U5 southeast extension is bundled with push measures in selected transport cells, the contribution to passenger transport-related carbon dioxide emission targets and primary energy consumption targets is low. Nevertheless, we demonstrate that the proposed assessment framework can support strategic transport planning in city regions. We argue for a change in perspective towards supply-side-oriented urban transport planning. Our proposed methodology is a first step in a different direction towards a sustainable mobility planning paradigm.

Urban Air Mobility (UAM): Airport shuttles or city-taxis?

In the last years, Urban Air Mobility (UAM) has been receiving increasing attention and even if the first services are expected to be launched shortly, there is still uncertainty about which type of commercial services (e.g., airport shuttles or city-taxis) will be implemented at an early stage, as well as which price point will be perceived as affordable by travelers. Based on data collected through a large-scale survey campaign in the Milan metropolitan area (Italy), in this paper passengers' value of travel time savings for different UAM services are estimated using advanced discrete choice modeling. Estimated mixed logit models allowed to comparatively analyze the differences between the two potential use cases, i.e., airport shuttle and city-taxi services. Results show a willingness to pay for UAM services from/to airports that is greater (in a range of 44%–57%) than for travelling within the metropolitan area, and greater (in a range of 31%–44%) for business travels than for other purposes, indicating that the most financially sustainable UAM services will potentially be available for airport-shuttle connections from/to central business districts.

Value of travel time savings for leisure trip in autonomous vehicles: Case study from the Tokyo Metropolitan Area

This study estimates the value of travel time savings (VTTSs) in autonomous vehicles (AVs) for leisure trip, using data collected from a stated-choice survey in the Tokyo Metropolitan Area, Japan. The survey was implemented through an internet monitoring program from February to March 2020, collecting 1,224 responses to stated-choice questions from 204 respondents. The survey was designed to request that the respondents choose AV or non-AV under six hypothetical conditions of travel time and cost when they are assumed to be using a car rental service to travel alone for a leisure purpose trip. Simple binary logit models are employed with two types of specifications in the utility function. First, the estimation results of the models without heterogeneity in the utility function showed that the VTTS in AVs is lower than that in non-AVs by approximately 7.3 % on average; however, the reduction of VTTS is not statistically significant. Second, the estimation results of the models incorporating observable heterogeneity into the marginal utility with respect to travel time also revealed that the individual’s preference of in-vehicle multitasking, age, and gender do not significantly affect the reduction of VTTS in AVs. Finally, changes in preference of AV-unique multitasking may affect VTTS, which should be monitored for future updating the VTTS guidelines.

Economic and environmental benefits of automated electric vehicle ride-hailing services in New York City

A precise, scalable, and computationally efficient mathematical framework is proposed for region-wide autonomous electric vehicle (AEV) fleet management, sizing and infrastructure planning for urban ride-hailing services. A comprehensive techno-economic analysis in New York City is conducted not only to calculate the societal costs but also to quantify the environmental and health benefits resulting from reduced emissions. The results reveal that strategic fleet management can reduce fleet size and unnecessary cruising mileage by up to 40% and 70%, respectively. This alleviates traffic congestion, saves travel time, and further reduces fleet sizes. Besides, neither large-battery-size AEVs nor high-power charging infrastructure is necessary to achieve efficient service. This effectively alleviates financial and operational burdens on fleet operators and power systems. Moreover, the reduced travel time and emissions resulting from efficient fleet autonomy create an economic value that exceeds the total capital investment and operational costs of fleet services.