Monash University, Institute of Transport Studies: World Transit Research (WTR)
Not a member yet
11112 research outputs found
Sort by
Incorporating geographic interdependencies into the resilience assessment of multimodal public transport networks
No full textSevere weather events, such as snowfall, flooding and storms, may affect wide geographical areas and adversely impact discrete transport infrastructure networks (e.g. road, rail) at the same time, thus revealing the existence of geographic interdependencies between these networks. In this paper, we develop two accessibility-based measures to assess the impact of geographic interdependency on resilience based on the concepts of redundancy and substitutability, respectively. These measures are applied to the railway and long-distance bus networks in Scotland. Results reveal that the combined effect of redundancy and substitutability on the accessibility of locations offered by these discrete modes is reduced due to geographic interdependencies, with the extent of losses being positively associated with the spatial footprint of potential events. The results can be used to identify parts of the network where the potential impacts of geographic interdependencies are greatest, and thus require more in-depth scrutiny by network managers
The positive impact of transit-oriented-development characteristics on Metro Station usage: A case study of Tehran\u27s metro stations and TOD index calculation
No full textTransit-Oriented Development (TOD) facilitates the creation of more walkable cities. To implement TODs, urban planners need a mechanism to delineate TOD levels so they can envision future planning trajectories. This study offers an approach to developing scores for TODs within Tehran, a metropolitan area with metro stations and Bus Rapid Transit that facilitate public transportation usage. TODs exhibit distinct characteristics when compared to other areas within a city. Furthermore, TODs vary in their levels of integration across transit, commerce, and residential, necessitating policies specific to each TOD. The main objective is 1) To identify the factors that best define TODs for metro stations and 2) To develop a TOD index to measure the TOD score. We used three different spatial units of measurement to define a range of metrics to identify how effective TODs work with different characteristics. The spatial units include: 1. Thiessen polygons 2. the walkable distance of the transit nodes and 3. Thiessen polygons without the walkable distances. The main criteria we used are travel behavior, walkability, accessibility, transportation inclusivity, network attribute, trip generation rate, and land use. The metrics are weighted based on the correlation results with the usage rate. A Negative Binomial regression was developed to find the metrics that are significantly influential on the usage rate of the metro stations. Results indicate that all criteria except the land use are significantly correlated with the usage rate of metro stations
Identifying human mobility patterns using smart card data
No full textHuman mobility is subject to collective dynamics that are the outcome of numerous individual choices. Smart card data which originated as a means of facilitating automated fare collection has emerged as an invaluable source for analysing mobility patterns. A variety of clustering and segmentation techniques has been adopted and adapted for applications ranging from market segmentation to the analysis of urban activity locations. In this paper we provide a systematic review of the state-of-the-art on clustering public transport users based on their temporal or spatial-temporal characteristics as well as studies that use the latter to characterise individual stations, lines or urban areas. Furthermore, a critical review of the literature reveals an important distinction between studies focusing on the intra-personal variability of travel patterns versus those concerned with the inter-personal variability of travel patterns. We synthesise the key analysis approaches as well as substantive findings and subsequently identify common trends and shortcomings and outline related directions for further research
Trajectory planning at a signalized road section in a mixed traffic environment considering lane-changing of CAVs and stochasticity of HDVs
No full textConnected and automated vehicles (CAVs) are projected to bring significant benefits to traffic efficiency and driving comfort. However, the realization of full CAV penetration rate will take a long time. In this paper, a framework is proposed for planning the trajectories of vehicles at a signalized road section in a mixed traffic environment consisting of CAVs, human-driven vehicles (HDVs) and connected and automated buses (CABs). In the proposed trajectory planning framework (TPF), both the lane-changing (LC) behavior of CAVs and the stochasticity of HDVs are considered. The whole TPF is composed of a planning module, a running module, and a switching module. In the planning module, the mixed integer programming (MIP) models for trajectory planning with/without LCs are formulated to optimize the trajectories of CAVs/CABs. A parsimonious algorithm is designed to determine a suitable planning time horizon for the MIP models. The running module and the switching module are designed to ensure the driving safety of vehicles. To consider the stochasticity of HDVs, the concept of -trajectory is employed in simulations to produce predicted trajectories of HDVs, while the actual trajectories of HDVs are generated by a stochastic car-following model. Here, is a parameter between 0 and 1 related to one randomly changing parameter of HDVs, and -trajectory is a series of predicted trajectories generated for HDVs based on the value of . A rolling time horizon scheme is applied for TPF to account for the time-varying traffic situations. Numerical experiments under different traffic states and market penetration rates (MPRs) of CAVs/CABs are conducted to validate the performance of the proposed TPF. The average improvement in travel time and fuel consumption can reach up to 28.9 %, 17.8 % and 52.2 %, 35.3 % under medium and heavy traffic, respectively, and the average improvement in driving comfort is over 20 % in most traffic scenarios. The comparison experiment without fixed rolling time window (FTW) shows the advantage of setting FTW in adapting to the time-varying traffic situations, especially under heavy traffic. The sensitivity analysis shows that the values of and associated with -trajectory can affect the performance of the proposed TPF in varying degrees. Finally, the length of the control zone is suggested to be set to 300–500 m
A novel route-based accessibility measure and its association with transit ridership
No full textTransit systems play a key role in improving access to job opportunities and basic services such as health and education. Most studies in the literature calculate transit accessibility using traditional place-based indicators that measure accessibility at a given location. However, because transit routes are the main unit of analysis in most approaches for planning and operation of transit systems, these accessibility indicators provide limited information to inform transport planning at the route-level. In addition, previous studies have demonstrated the methodological limitations of traditional place-based accessibility metrics to study the association between accessibility and transit ridership. In this paper, we propose a novel route-based accessibility measure to fill the mentioned gaps. The indicator measures the average level of access to opportunities provided by a given transit route to the population in its extended catchment area. This indicator is flexible enough that it can be calculated using different travel cost functions and can be applied to measure access to different activity types for the whole population or for specific groups. To illustrate the applicability of the proposed indicator, we calculated the employment accessibility provided by all routes of the transit system of Fortaleza, Brazil. We also show that the proposed indicator has greater predictive power of transit ridership than other route-level accessibility measures found in the literature. This paper provides a methodological contribution that could help transport planners incorporate accessibility analysis into transit system redesign projects, and help practitioners anticipate what accessibility impacts and subsequent changes in transit ridership could be expected from route-level service changes, and to examine the influence of accessibility on transit ridership
Measuring route diversity in spatial and spatial-temporal public transport networks
No full textRoute diversity is a pivotal metric for evaluating the redundancy of transportation networks, a fundamental aspect of system resilience. This study provides a comprehensive exploration of route diversity in multimodal public transport systems, specifically considering the unique characteristics of bus networks. Our research introduces a two-pronged approach to measuring route diversity within spatial public transport networks, delving into service-based and infrastructure-based perspectives. The former assesses redundancy against transit service disruptions by factoring in transit line overlaps, while the latter evaluates redundancy against infrastructure-related interruptions by considering overlapping road segments on which transit lines rely. In addition, the study advances by modelling public transport systems as multilayer spatial-temporal networks, integrating time-variable service frequency and travel time uncertainty, which enables us to derive route diversity for origin-destination (O-D) pairs across different time periods.
We present a case study of the multimodal public transport network in Jiading District, Shanghai, revealing a power-law distribution of the route diversity. The results unveil O-D pairs with lower route diversity, underscoring their lack of resilience against various disturbances. Lower service-based route diversity suggests the necessity of enhancing service frequency and bolstering cross-line combined transit scheduling, while lower infrastructure-based route diversity could warrant the design of road-diversified transit lines, especially within bus corridors. Besides, relative route diversity between the two indices highlights specific O-D pairs with notable disparities in service and infrastructure redundancy. This difference is correlated with the distance between O-D pairs and the road network\u27s configuration. This analysis underscores the method\u27s potential to offer more relevant insights to public transport planners and operators for adjusting transit lines and schedules through a resilience-focused lens
Exploring autonomous bus users’ intention: Evidence from positive and negative effects
No full textThe introduction of autonomous buses (ABs) in many countries addresses traditional bus operation challenges, but overlooks critical perceived risks, like functional, safety, and security issues, affecting autonomous driving technology acceptance. This research uses the mental accounting theory to investigate both the positive and negative effects of the intention to use ABs. A hybrid discrete choice model captures latent and observed factors and considers COVID-19\u27s impact on travel mode preferences. Results show that both latent and observed factors significantly affect AB adoption intention, including compatibility, relative advantage, safety/security risks, perceived risks, in/out-of-vehicle time, and travel cost. Trial rides positively impact adoption intention. Familiarity with unmanned tech also affects choice of shared bicycles and ABs, allowing for tailored promotional programs. The conclusions herein offer insights for bus operators, manufacturers, and city governments to integrate ABs into public transport systems effectively
Transit-induced socioeconomic ascent and new metro stations in Helsinki Metropolitan Area: Distinct effects on renters, homeowners, and pre-existing housing dwellers
No full textIn recent years, transit-oriented developments have been studied from different angles in different countries. Question has been raised whether public investments in transportation trigger the areas nearby to gentrify or even cause the affordability paradox for the low-income households if they cannot afford to live in the accessibility improved areas. This article contributes to the literature of transit-induced neighbourhood change by estimating the short-term causal effect of accessibility improvements on neighbourhoods\u27 household income, share of highly educated individuals, and share of low-income households, separating between renters and residents in the existing and new housing stock. We are using a quasi-experimental study design with propensity score matching and difference-in-differences regression setup to analyse the socioeconomic changes in the areas close to the newly built metro stations. Overall, we identify a positive effect on the share of residents with higher educations, but don\u27t see effects on median household income or share of low-income households. However, on closer examination, we find short-term transit-induced changes for residents in old housing stock, and to some extent for homeowners, but for the renters we don\u27t find significant results. The findings of this article show that short-term transit-induced neighbourhood change occurs in areas where accessibility has improved
Examining the performance of transit systems in large US metropolitan areas
No full textThe assessment of transport systems has traditionally focused on congestion and ridership as its core performance measures. These perspectives fail to account for the actual service people seek from the transport system—the ability to reach destinations. Recent studies have shifted to focus on accessibility as a performance indicator, but do not address the question whether the observed accessibility is sufficient for meeting people’s daily needs. This paper contributes to the accessibility literature by (1) applying a people-centered approach to the performance assessment of transit systems and (2) exploring the factors explaining the differences in performance between regions. The paper proposes the Accessibility Sufficiency Index (ASI) as a performance standard. The ASI is based on a sufficiency threshold representing an accessibility level that is assumed to enable adequate access to destinations. The paper uses neighborhood transit job accessibility data to calculate separate ASI scores for different sufficiency thresholds for 49 large US metropolitan areas. Regression analyses show that transit system performance is shaped most strongly by transit vehicle revenue miles, mixed land uses, and activity centering. Importantly, the size of these effects varies by the employed sufficiency threshold, suggesting that transportation and land use factors affect transit performance at different spatial scales. The results have implications for the ways we evaluate transport and transit systems and for our understanding of the factors that affect their performance
A stochastic hub location and fleet assignment problem for the design of reconfigurable park-and-ride systems
No full textPark-and-ride systems have the potential to improve the efficiency of transportation networks by providing targeted shared mobility services. The design of a park-and-ride system depends on its role in regards to the broader transportation network. Reconfigurable park-and-ride systems aim to provide complementary shared mobility services in the context of varying travel demand scenarios, such as special events, network maintenance operations or non-recurrent perturbations. The design of reconfigurable park-and-ride systems involves the location of access and egress hubs for shared mobility services. We study an extended version of this hub location problem with integrated fleet assignment decisions. We consider stochastic scenarios representative of varying travel demand and traffic conditions on the network and propose a two-stage stochastic integer programming hub location formulation for this problem. First-stage variables represent hub location decision while second-stage variables represent both scenario-based transportation flows and fleet assignment decisions. The latter represent shared mobility service vehicles and they are modeled as integer variables. We develop solution methods to solve this two-stage stochastic integer programming hub location formulation. Exact approaches based on the L-shaped method are proposed with single- and multi-cut configurations. Valid inequalities along with a tight lower bound for the generation of optimality cuts are presented. We also develop a matheuristic to solve larger problem instances. We report numerical results on problem instances based on real data of the city of Lyon, France. We show how stochastic scenarios representative of varying demand and traffic conditions can be generated from such data. Our experiments demonstrate the benefits of this integrated modeling approach for designing efficient reconfigurable park-and-ride systems while considering fleet assignment decisions