ORCID Profile
0000-0003-0108-1466
Current Organisation
University of Queensland
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Transport Engineering | Information Systems | Database Management | Autonomous Vehicles | Mechanical Engineering | Computer-Human Interaction
Application Tools and System Utilities | Automotive Equipment | Road Safety | Road Passenger Movements (excl. Public Transport) | Electronic Information Storage and Retrieval Services |
Publisher: SAGE Publications
Date: 16-07-2021
DOI: 10.1177/03611981211016458
Abstract: Heavy vehicle crashes incur significant economic and social costs. Although most crashes are considered to be related to driver error, the effects of vehicle defects are major in many crashes. Therefore, various vehicle inspections including Queensland’s Certificate of Inspection (COI) scheme have been implemented to improve the safety of heavy vehicles. This study analyzes the trends of heavy vehicle crashes and their relationships with COI results. Longitudinal data provided by Queensland’s Department of Transport and Main Roads for the period of June 2009 through December 2013 were used to perform the analyses. The data include 474,640 programmed inspections and 2,274 crashes in which heavy vehicles were involved. The results show significant relationships between the monthly average inspection failure rate as well as the monthly average failure severity level, and the total number of heavy vehicle crashes. The results also reveal significant relationships between the monthly average inspection failure rate, average vehicle age, as well as monthly average mean maximum temperature, and the number of defect-related crashes. The implications of these results are discussed with respect to heavy vehicle safety policies.
Publisher: Springer Berlin Heidelberg
Date: 2008
Publisher: Center for Transportation Studies
Date: 08-2013
Abstract: We are exploring ways to capture the temporal and spatial dimensions of the use of public transit. Specifically, we are investigating how different land uses affect the spatial and temporal demand for public transit services. Spatially, the availability of new data collection technology in public transit allows us to examine transit demand at the in idual stop level. Our hypothesis, however, is that transit users' activity may not be originated from or destined to an in idual stop per se rather, the activity is associated with a specific location in the vicinity of the stop, and this location may be "covered" by several adjacent transit stops. More importantly, understanding the transit demand at this aggregate level (an aggregate "catchment" area) can enhance the ability to define a specific land-use type and the temporal characteristics related to passengers' activities. Temporally, we seek to understand the relationship between the demand for public transit service at specific times of the day and the associated land uses that may strongly influence the timing of that demand. To explore these dimensions, this study: 1) proposes a method of stop aggregation 2) generates transit service areas based on these aggregated stops 3) develops a set of metrics to better represent land-use types within these service areas and 4) examines the spatial and temporal characteristics of transit demand for these service areas. These methods are applied to a case study using land-use and transit demand data from the Minneapolis–St. Paul metropolitan area.
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-1997
Publisher: SAGE Publications
Date: 2012
DOI: 10.3141/2303-03
Abstract: The development of integrated land use–transport model systems has long been of interest because of the complex interrelationships between land use, transport demand, and network supply. This paper describes the design and prototype implementation of an integrated model system that involves the microsimulation of location choices in the land use domain, activity–travel choices in the travel demand domain, and in idual vehicles on networks in the network supply modeling domain. Although many previous applications of integrated transport demand–supply models have relied on a sequential coupling of the models, the system presented in this paper involves a dynamic integration of the activity–travel demand model and the dynamic traffic assignment and simulation model with appropriate feedback to the land use model system. The system has been fully implemented, and initial results of model system runs in a case study test application suggest that the proposed model design provides a robust behavioral framework for simulation of human activity–travel behavior in space, time, and networks. The paper provides a detailed description of the design, together with results from initial test runs.
Publisher: Institute for Operations Research and the Management Sciences (INFORMS)
Date: 08-2007
Abstract: The Transportation Science and Logistics (TSL) Society Dissertation Prize Competition is the oldest and most prestigious competition for doctoral dissertations in the field. The 2006 TSL dissertation prize committee consisted of Professor Michel Bierlaire (École Polytechnique Fédérale de Lausanne), Professor Ann C bell (University of Iowa), Professor Alan Erera (Georgia Institute of Technology), Professor Donald Hearn (University of Florida), and Professor Mark Hickman (University of Arizona). Eligibility was limited to doctoral dissertations completed between June 1, 2005, and May 31, 2006, in the general area of transportation science and logistics. To be considered, a dissertation must have been nominated by the author’s thesis supervisor. This year we received 26 nominations from 24 universities and 10 countries, representing such erse areas as vehicle routing, vehicle scheduling, traveler behavior, activity analysis, logistics, and supply chain management. This year’s pool of dissertations was exceptional in both its breadth and depth, showing remarkable theoretical and practical insights into many very interesting problems in transportation and logistics. With the large number of submissions and their exceptional quality, it was not easy for the committee to select a first place winner and an honorable mention. I would like to thank the authors, their advisors, and the prize committee for their part in this effort to recognize and honor the field’s outstanding doctoral researchers. Awards were announced at the TSL meeting at the 2006 INFORMS meeting in Pittsburgh. Perhaps without saying, the theses nominated for the TSL Dissertation Prize are distinguished by the fact that they were nominated for the award. Each dissertation makes a unique and valuable contribution to transportation science and logistics, and all entrants and their advisors deserve our sincere congratulations. Abstracts for the 26 dissertations follow awardees are listed first, and finalists’ abstracts follow in alphabetical order by author. First Place: Christian Liebchen, Technische Universität Berlin, Germany. Advisors: Rolf H. Möhring and Karl Nachtigall. Title: “Periodic Timetable Optimization in Public Transport”. Honorable Mention: Anne Goodchild, University of California, Berkeley. Advisor: Carlos Daganzo. Title: “Crane Double Cycling in Container Ports: Algorithms, Evaluation, and Planning”.
Publisher: The University of Queensland
Date: 04-2022
DOI: 10.14264/93110DE
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2003
Publisher: Springer Science and Business Media LLC
Date: 08-2010
Publisher: SAGE Publications
Date: 2012
DOI: 10.3141/2283-06
Abstract: This paper presents an efficient algorithm that finds the intermodal optimal tour (origin to origin) in a time-dependent transportation network while the algorithm implicitly solves the park-and-ride facility choice problem with the inherent park-and-ride constraints for a traveler with a sequence of destinations to visit. To solve the problem, a network expansion technique that captures the constraints of park-and-ride behavior in the model and that transforms the park-and-ride choice problem into a dynamic network flow problem is introduced. An efficient iterative labeling algorithm that finds the optimal intermodal tour to serve the sequence of activities is also introduced. Multisource shortest-path runs are used in the iterative labeling algorithm to find the optimal tour with several intermediate destinations in an efficient manner. The performance of the algorithm is compared with the performance of existing approaches, and improvement is indicated. The solution method proposed benefits from the advantages of Dijkstra's shortest-path algorithm, which is made possible by (a) a nontrivial transformation of the original problem into a dynamic network flow problem and (b) an innovative use of a multisource shortest path in the context of origin–destination choice. The solution algorithm integrates time-dependent auto and transit shortest-path algorithms to find the optimal tour. The algorithm is implemented, coded, and tested on a real network, and the results are promising.
Publisher: American Society of Civil Engineers
Date: 04-08-2006
DOI: 10.1061/40799(213)39
Publisher: Elsevier BV
Date: 08-1995
Publisher: SAGE Publications
Date: 2012
DOI: 10.3141/2291-11
Abstract: This research proposes a method to estimate a road mask in airborne imagery to improve vehicle detection and tracking. The road mask can remove false detections and reduce computation time. The road mask was estimated on the basis of smoothed (interpolated) positions of the vehicles tracked by the short-term and long-term trackers in the software tool “tracking and registration of airborne video image sequences” (TRAVIS) in a fixed number of frames (i.e., one cycle). First, raw vehicle positions that were obtained from TRAVIS were smoothed with a Kalman filter. Second, the slope of the roadway was estimated based on the smoothed positions of these vehicles. Third, falsely detected vehicles were removed if the slope of the lines that connected two vehicles in the same lane were close to the slope of the roadway. Finally, the road mask was generated according to the minimal and maximal intercepts of the approximated roadway edges in one cycle. Experimental results showed that the estimation of the road mask was accurate and that the improvement in the correct detection and tracking rate and in the computation time was significant.
Publisher: Elsevier BV
Date: 12-2007
Publisher: Elsevier BV
Date: 12-2018
Publisher: Informa UK Limited
Date: 04-2005
Publisher: Institution of Engineering and Technology (IET)
Date: 12-11-2018
Publisher: SAGE Publications
Date: 2010
DOI: 10.3141/2196-07
Abstract: This paper discusses details of developing an optimal zone-based vehicle evacuation strategy based on an optimization–simulation approach. The optimal egress strategy is obtained by solving a universal quickest flow problem, and the solution is implemented and evaluated in a mesoscopic simulation model. Evacuees would follow optimal routes to safe locations outside the hot zone and then select behaviorally realistic routes to their final destinations. Background traffic is included in the model to simulate more realistic traffic conditions. The route choice of background traffic in response to the evacuation strategy and driver information strategies is carefully addressed. Operational issues such as temporal loading intensity and queuing at parking lots are also modeled and discussed. The modeling framework has been applied to a bomb threat scenario at a football stadium. The case study shows that the proposed methods generate reasonable and meaningful results for the intended no-notice scenario.
Publisher: SAGE Publications
Date: 2013
DOI: 10.3141/2382-19
Abstract: This study exploits electronic fare collection data to examine the symmetry of boardings and alightings along a transit route. The symmetry of boardings and alightings is arguably the most important concept in the estimation of travel distances such as average trip lengths and passenger miles from data from entry-only fare collection systems. The paper shows the ways such data can be used to examine the symmetry of boardings and alightings through travel patterns in spatial and temporal dimensions. A novel method for aggregating stops, especially for the nearest stops in the opposite direction, is used to compare boardings in one direction with alightings in the opposite direction. Spatially, the method allows examination of the characteristics of boardings and alightings in a spatial dimension. Temporally, the method examines whether a specific and symmetric passenger flow is observed between specific periods (e.g., between morning and afternoon peaks). A case study of the Minneapolis–Saint Paul, Minnesota, region is performed by using automatically collected data from Metro Transit. Automatic fare collection data reveal considerable variation in passenger flow between specific periods. The use of automated passenger-counting data shows this variation to be statistically significant when both temporal and spatial symmetry are examined on an in idual day.
Publisher: American Society of Civil Engineers (ASCE)
Date: 05-2020
Publisher: Springer Science and Business Media LLC
Date: 27-07-2014
Publisher: Springer Science and Business Media LLC
Date: 16-10-2014
Publisher: SAGE Publications
Date: 2012
DOI: 10.3141/2284-05
Abstract: A simple but efficient algorithm is proposed for finding the optimal path in an intermodal urban transportation network. The network is a general transportation network with multiple modes (auto, bus, rail, walk, etc.) ided into the two major categories of private and public, with proper transfer constraints. The goal was to find the optimal path according to the generalized cost, including private-side travel cost, public-side travel cost, and transfer cost. A detailed network model of transfers between modes was used to improve the accounting of travel times during these transfers. The intermodal path algorithm was a sequential application of specific cases of transit and auto shortest paths and resulted in the optimal intermodal path, with the optimal park-and-ride location for transferring from private to public modes. The computational complexity of the algorithm was shown to be a significant improvement over existing algorithms. The algorithm was applied to a real network within a dynamic traffic and transit assignment procedure and integrated with a sequential activity choice model.
Publisher: SAGE Publications
Date: 2012
DOI: 10.3141/2284-04
Abstract: The concept of a hyperpath was introduced for handling passenger strategies in route choice behavior for public transit, especially in a frequency-based transit service environment. This model for handling route choice behavior has been widely used for planning transit services, and hyperpaths are now applied in areas beyond public transit. A hyperpath representing more specific passenger behaviors on a network based on transit schedules is proposed. A link-based time-expanded (LBTE) network for transit schedules is introduced in the network each link represents a scheduled vehicle trip (or trip segment) with departure time and travel time (or arrival time) between two consecutive stops. The proposed LBTE network reduces the effort to build a network based on transit schedules because the network is expanded with scheduled links. A link-based representation of a hypergraph with existing hyperpath model properties that is directly integrated with the LBTE network is also proposed. Transit passenger behavior was incorporated for transfers in the link-based hyperpath. The efficiency of the proposed hyperpath model was demonstrated. The proposed models were applied on a test network and a real transit network represented by the general specification of Google's transit feed.
Publisher: SAGE Publications
Date: 2011
DOI: 10.3141/2263-16
Abstract: As fare and data collection technology has developed, the resolution of collected data has reached the level of the in idual traveler in investigations of transit passenger behavior. This paper investigates the use of these data to estimate passenger origins and destinations at the level of in idual stops. Because of a lack of information from the fare collection system, researchers still need some estimate of passengers' alighting stops to complete each passenger trip chain on a specific day. Automated fare collection (AFC) and automated vehicle location (AVL) systems are the inputs to the estimation. Instead of typical AVL data, the paper proposes two models to estimate the alighting stop both consider passenger trip chaining by using AFC data, transit schedule data (Google's General Transit Feed Specification), and automated passenger counter (APC) data. The paper validates the model by comparing the output to APC data with vehicle location data (APC-VL) and performs sensitivity analyses on several parameters in the models. To detect transfer trips, the new models propose a submodel that takes into account the effect of service headway in addition to some typical transfer time thresholds. Another contribution of this study is the relative relaxation of the search in finding the boarding stops, which enables the alternative algorithm to detect and fix possible errors in identification of the boarding stop for a transaction. As a result, the paper provides algorithms for the proposed models and sensitivity analysis for several predefined scenarios. The results are based on data and observed bus passenger behavior in the Minneapolis–Saint Paul, Minnesota, area.
Publisher: Elsevier
Date: 2007
Publisher: SAGE Publications
Date: 2009
DOI: 10.3141/2091-10
Abstract: As part of disaster mitigation and evacuation planning, planners must be able to develop effective tactical and operational strategies to manage traffic and transportation needs during an evacuation. One aspect of evacuation planning is the estimation of how many people must be evacuated to provide strategies that are responsive to the number and location of these people. When such estimates are available, it may be possible to implement tactical and operational strategies that closely match the likely demand on the road network during the evacuation. With short notice for an evacuation, people may need to be evacuated directly from current locations. In addition, for some disasters, the spatial extent of the evacuated area may change over time. This problem may be exacerbated by congestion around the evacuated area. An estimation process is proposed for a short-notice evacuation. The method uses on-hand data typically generated through existing travel demand models at many metropolitan planning organizations. It estimates demand using convenient models for trip generation, trip distribution, and travel time generation for these trips, considering a staged evacuation. These demand estimates feed a dynamic simulation model, DynusT, that is used to model the supply characteristics of the roadway network during the evacuation. Such models can be applied using a case study based on a short-notice flooding scenario for Phoenix, Arizona.
Publisher: Springer Berlin Heidelberg
Date: 2001
Publisher: Elsevier BV
Date: 2019
Publisher: Institute for Operations Research and the Management Sciences (INFORMS)
Date: 08-2001
DOI: 10.1287/TRSC.35.3.215.10150
Abstract: This paper describes an analytic model that determines the optimal vehicle holding time at a control stop along a transit route. This model is based on a stochastic transit service model presented by Andersson and Scalia-Tomba (1981) and enhanced by Marguier (1985). The use of a stochastic service model allows greater realism in the analytic modeling. Making use of these results, the paper presents an analytic model that may be used to determine the optimal holding time for a vehicle at a control stop. As it is formulated, the single vehicle holding problem is a convex quadratic program in a single variable, and is easily solved using gradient or line search techniques. The analytic holding model overcomes two noted problems in the literature: it includes stochastic service attributes of vehicle running times and passenger boarding and alighting processes, and the model may be used for real-time control purposes. The use and potential benefits of the model are illustrated in a simple ex le. This model may be useful in developing a computerized decision support system to enhance the effectiveness of transit operational decision-making.
Publisher: SAGE Publications
Date: 2013
DOI: 10.3141/2350-05
Abstract: Willing-to-walk distance was investigated as a means of measuring spatial accessibility of bus stops and of examining the effectiveness of alternative methods of generating mutually exclusive transit service areas at the route level. First, the walking distance to and from a transit stop was investigated with onboard survey data. Two methods in geographical information systems—the combination of Thiessen polygon and buffer and the network distance-based service area—were compared as strategies for generating mutually exclusive service areas. For the examination of the effectiveness of these two methods, all mutually exclusive service areas were validated with a spider diagram generated from an onboard survey. Measures of urban form were also statistically tested for comparison of the two methods. A case study of a single route, serving the Minneapolis–Saint Paul, Minnesota, metropolitan area, was performed with data from various sources, such as Google's General Transit Feed Specification, an onboard survey, parcel-level land uses, and the U.S. Census street network. Validation with onboard survey data demonstrates the strengths of each method. Results also show that the network-based service area, a popular geographical information system method for service area analysis, does not yield a more meaningful strategy for generating mutually exclusive transit catchment areas, especially when spacing between stops is very small.
Publisher: Kluwer Academic Publishers
Date: 2004
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: Elsevier BV
Date: 11-2023
Publisher: Springer Berlin Heidelberg
Date: 2008
Publisher: SAGE Publications
Date: 2012
DOI: 10.3141/2276-05
Abstract: The development and the application of a stop aggregation model (SAM) for a transit network based on Google's General Transit Feed Specification (GTFS) are detailed. The use of GTFS has been drawing attention in the public transit planning arena. A SAM is proposed to explore how to use this innovative data source in a transit network. The hypothesis is based on the fact that transit users' activity may not originate from or be destined to an in idual stop per se. Rather, the activity is associated with a specific location in the vicinity of the stop, and this location may be covered by several adjacent transit stops. Therefore, the goal of a SAM is to define a generalized definition of a stop that more closely matches the nature of locations that serve as passenger origins and destinations. To define an aggregate area around a transit stop or station, three parameters are investigated: distance or proximity, text in the stop description, and the catchment (service) area. These aggregated stop groups can be represented as a single node in the transit network, depending on the level of aggregation desired. A case study of the Minneapolis–Saint Paul metropolitan area in Minnesota is performed with GTFS data from Metro Transit. A SAM can be practically applied in estimating aggregate-level origin–destination flows and linking with onboard survey data.
Location: United States of America
Location: United States of America
Start Date: 08-2019
End Date: 12-2024
Amount: $330,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 11-2022
End Date: 06-2024
Amount: $548,940.00
Funder: Australian Research Council
View Funded Activity