Monash University, Institute of Transport Studies: World Transit Research (WTR)
Not a member yet
11112 research outputs found
Sort by
Integrating environmental issues into the design of mobility plans: Insights from French practices
No full textLocal authorities have a strategic role in mitigating the environmental impacts of the transport sector. However, they struggle to integrate environmental issues into their decision-making processes, especially planning. In the European context of the Sustainable Urban Mobility Plan approach and Strategic Environmental Assessments (SEAs), this paper scrutinises three French localities to determine the current best practices and limitations for designing mobility plans and integrating environmental issues. Several limitations are identified: (1) limited expertise in defining and characterising actions and objectives, which complexifies plans\u27 design, understanding, and monitoring; (2) a lack of a framework to conduct long-term quantitative environmental assessments and to use the results to influence decision effectively; and (3) monitoring processes are barely described in the documents, and the planning horizon where objectives are defined is not in sync with the indicators’ mandatory evaluation period. This French case study thus reveals that European planning practices must be further analysed and improved to deal with the rising environmental concerns, e.g. through an operational framework to design mobility plans with effective integration of environmental issues
Re-envisioning the Park-and-Ride concept for the automated vehicle (AV) era with Private-to-Shared AV transfer stations
No full textCities implemented park-and-ride (PNR) systems to decrease congestion in dense urban areas while providing transit options to travelers who live in a city\u27s low- to medium-density regions. The success of PNR systems is mixed, as they suffer from several disadvantages, namely, the uncertainty of parking locations and infrequent and/or unreliable transit services, and the fact that travelers still need to walk to their destination. Motivated by the premise of PNR systems and the potential of automated vehicles (AVs), to address each of the shortcomings of PNR systems, this study proposes a future system with near-ubiquitous AVs where travelers transfer from privately owned AVs (PAVs) to shared-use, shared-ride AVs (SAVs), called a PAV-SAV transfer system. This study proposes a modeling framework to assess the potential market share of the PAV-SAV transfer system and the network impacts (e.g., congestion, vehicle miles traveled) of the proposed system. Finally, the study identifies good designs for the PAV-SAV transfer system using scenario analysis. The critical design variables are the location of transfer stations, the capacity of SAVs, and the transfer station connector links. For the Greater Los Angeles area, the computational results show a market share for PAV-SAV of almost 18% for person trips terminating in downtown Los Angeles. In all scenarios, the proposed PAV-SAV system decreases vehicle hours traveled (VHT) across the whole network with significant decreases in the urban core. For all designs, the PAV-SAV system decreases vehicle miles traveled (VMT) compared to a network without PAV-SAV transfer stations, albeit only slightly. Locating transfer stations closer to the urban core, increasing vehicle capacities, and connecting transfer stations to both arterial links and highway links improves network performance (i.e., VMT and VHT) and increases the market share of the PAV-SAV system
Unraveling the inconsistency in captive riders’ behaviors and attitudes within public transportation service usage: An integrated modeling approach
No full textFostering enduring patronage among passengers for public transportation (PT) services is crucial for sustaining ridership. However, a significant concern arises from the inconsistency between passengers\u27 negative attitudes and their robust patronage behaviors toward PT services, particularly evident among the captive riders. This paradox entails the risk of these passengers potentially shifting to alternative transport modes in the future, thereby diminishing ridership. To unravel the intricate dynamics inherent in the relationship between captive riders\u27 attitudes and behaviors, this study introduces a novel integrated model merging Satisfaction-Loyalty Theory (SLT) with Theory of Planned Behavior (TPB). The integrated model seeks to enhance the comprehension of the mechanisms that drive captive riders\u27 ongoing utilization of PT services, specifically within the context of attitude-behavior inconsistency. Evident in a case study involving 637 samples collected in Dalian, China, the integrated model not only shows excellent goodness-of-fit but also outperforms both the conventional SLT and TPB frameworks. It excels in explaining why captive riders may persist in their behaviors towards the service even in the face of dissatisfaction and highlights how the perceived service quality shapes their attitudes and behaviors. This substantially contributes to the development of targeted service improvement strategies for sustaining captive riders’ continued patronage
On the right track? Energy use, carbon emissions, and intensities of world rail transportation, 1840–2020
No full textThe history of rail transport can offer valuable insights for future energy transitions due to its importance in promoting clean mobility. There is a complex interplay between the evolution of the railway network, fuel consumption, efficiency, energy service, and CO2 emissions that requires further exploration. We developed a dataset that covers energy use in all stages of rail transportation, as well as the length of track, energy service, and CO2 emissions at the world scale. To deal with missing data we utilized machine learning techniques for the first time in a historical energy reconstruction study. Our analysis reveals that for world rail transport (1) the final-to-useful efficiency has increased by 30-fold from 1840 to 2020, mainly due to the replacement of steam trains with diesel and electric ones, (2) the peak in final energy use occurred in the 1940s, while useful energy use and transport service continue to grow, (3) there was a reduction in the energy (carbon) intensity from approximately 20 to 0.2 MJ/tkm (2 to 0.02 kg CO2/tkm) between 1840 and 2010, due not only to the increase in final-to-useful efficiency but also to rising occupancy, better operating conditions, and reduced losses by the passive system
Transit to parks initiatives in the U.S. and Canada: Practitioners’ perspectives
No full textAs large open spaces, such as national and regional parks, have become popular as recreational destinations, car dependency to access those open spaces has created capacity challenges. Due to these issues, transit-to-parks (T2P) initiatives—public transportation services connecting populated areas to large parks—have gained global traction. Limited research has examined these sustainability initiatives, and more knowledge is needed about how these initiatives are created and function. To address these gaps, this study explores motivations, facilitators, and challenges related to T2P initiatives in the U.S. and Canada. We conducted semi-structured interviews with 28 practitioners involved in the planning or operation of T2P initiatives in the two countries. Motivations for T2P included parking and congestion issues, environmental concerns, equity, and economic development. Facilitators of T2P initiatives included robust partnerships, community engagement, and advocacy efforts, emphasizing the importance of tailored narratives and coalition-building. The primary challenges mentioned were limited funding and labor, inadequate infrastructure, and siloed agencies and politics. This study reveals the complex dynamics of T2P initiatives and provides practical implications for transit agencies, public lands agencies, and community advocates seeking to enhance more sustainable and equitable access to nature
Quantifying impacts of sustainable transport interventions in Scotland: A system dynamics approach
No full textTo overcome the challenge transport presents to net zero, the Scottish Government has proposed a series of interventions to significantly reduce transport emissions and car kilometres travelled. This paper develops, validates and applies a system dynamics model of the Scottish road passenger transport sector to interrogate key proposed interventions up to 2030: namely, modal shifting sub-10 km car journeys to active travel, modal shifting medium-length car journeys to buses, achieving a majority electrification of the bus fleet, and replacing 50 % of petrol/diesel cars with electric vehicles. Results indicate government targets can be met, but only as a result of multiple interventions. Modal shifting of medium-length car journeys and private car electrification are predicted to be the most effective interventions for emissions reduction, although these measures alone do not attain reduction targets. Results further indicate that realising the reduction in car kilometres does not guarantee the emissions target will also be achieved
Assessing flood resilience of urban rail transit systems: Complex network modelling and stress testing in a case study of London
No full textWhile the growing prevalence of extreme floods worldwide constantly compromises the service delivery of urban rail transit systems (URTSs), limited research attempts to measure the resilience of URTSs to flood disruptions. This study marks the first quantitative assessment of URTS flood resilience, focusing on dynamic operational performance of service delivery under realistic flood disruption scenarios. A model is tailored to incorporate a broader range of real-world factors into complex network modelling than adopted previously, including physical URTS network features, plausible flood disruption scenarios, and resourcing for recovery. The results of the London URTS case study suggest that the loss of satisfied travel demand is approximately 1.8 million, 4.2 million, and 7.2 million for the 30-year, 100-year, and 1000-year floods, leading to anticipated revenue loss of £3.1 million, £6.8 million, and £11.4 million, respectively (subject to modelling assumptions). This study highlights that the popular normalised resilience index can capture system performance loss but not necessarily recovery time: this matters when there is a long tail to the recovery process. This study provides a meaningful quantitative approach to assessing the current level of system resilience and lays the groundwork for testing the effectiveness of potential interventions for disaster risk reduction in operation and management
Modeling the evacuation behavior of subway pedestrians with the consideration of luggage abandonment under emergency scenarios
No full textAs subway systems play a central role in connecting various modes of transport, such as trains and airplanes, passengers with luggage cases have become common sight in subway stations. During emergency situations such as fires or earthquakes, passengers carrying luggage are likely to abandon their luggage to escape. However, the impact of abandoned luggage on evacuation remains unclear. Current research does not analyze the forces on pedestrians carrying luggage on a physical level and lacks knowledge of the interaction mechanism between luggage and pedestrians. Therefore, this paper constructs a comprehensive model based on an improved social force model that considers pedestrians carrying luggage cases, ordinary pedestrians, and abandoned luggage cases. It simulates a complete situation where pedestrians carry to discard luggage during an emergency. Through the simulation of Qingdao Station, we explore the impact of discarded luggage cases on pedestrian evacuation in subway bottlenecks and the interaction mechanism between luggage cases and pedestrians. The results show that strategies that involve the removal of luggage in areas of bottlenecks such as stairs, escalator entrances, and gateways have a significantly negative impact on the efficiency of evacuation. The key factors affecting evacuation efficiency are the appearance and dissipation of blockages due to accumulated luggage. The luggage carrying rate and abandonment rate are primary determinants for the occurrence of blockages. When blockages cannot be resolved, discarding luggage cases helps in evacuation. The removal of luggage cases increases the individual speed but decreases the overall evacuation speed. Compared to scenarios without luggage abandonment, the arching effect formed in those with discarded luggage cases is more complex and unstable
Dynamic flow control model and algorithm for metro network under FIFO condition
No full textImplementing passenger flow control strategies is an effective approach to reducing commuter travel delays and ensuring crowd safety in a congested metro network. Due to the intricacy of the interweaving of passenger flows between various lines and stations, the development of a scientific passenger flow control strategy is challenging in the networked mode of operation. The first-in-first-out (FIFO) rule can ensure service fairness and optimal operation by accurate modeling passenger queuing dynamics, but it is rarely considered in existing studies. Inspired by the traditional dynamic traffic assignment models, we propose a novel passenger flow control model with the FIFO rule to find a more reasonable control strategy for a metro network. Unlike road traffic systems, the FIFO rule is formulated as a set of linear constraints to explicitly capture the passenger queuing properties at origin stations. The passenger flow control problem with the FIFO rule is then modeled as a mixed integer linear programming model, which can significantly reduce the model complexity. To reach a high-quality solution, we propose an efficient rolling horizon decomposition approach. In the algorithm, the planning horizon is rolled forward from the current time, and the effects of subsequent periods are considered at each iteration. Besides, a dynamic procedure for loading passengers is developed to evaluate the bounds between the proposed approach and other flow control strategies. The proposed model and algorithm are then applied to solve the problems in test and real metro networks. The numerical results demonstrate the validity of the model’s properties and the algorithm’s performance
An Autonomous Modular Public Transit service
No full textIn this work, we present a proof-of-concept investigation of Autonomous Modular Public Transit (AMPT) at a network scale and compare it with the traditional fixed-route, fixed-vehicle size transit service in terms of total cost, which consists of both agency’s capital and operational cost (including energy cost) and passenger time cost. We formulate and solve stylized design models for AMPT on a grid network in a range of demand density scenarios with both homogenous and heterogeneous distributions. The AMPT models explicitly account for pod joining and disjoining (and therefore en-route transfers of passengers) and potential energy savings due to pod train formation (pod platooning), which represent major departures from the traditional transit models in the literature. Numerical results find that AMPT, if designed properly, may save the total cost compared to traditional transit systems thanks to demand responsive pod train capacity, particularly in the low demand scenarios. The cost savings of AMPT are largely attributed to passenger time saving by en-route transfer; the agency cost of AMPT has a mixed picture. The load factor of AMPT generally improves over the traditional transit service. We also show how key parameter values may affect the AMPT costs through sensitivity analysis