| 1. |
- Amekudzi, A., et al.
(author)
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Assessing extrajurisdictional and areawide impacts of clustered brownfield developments
- 2003
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In: Journal of urban planning and development. - 0733-9488 .- 1943-5444. ; 129:1, s. 27-44
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Journal article (peer-reviewed)abstract
- Brownfields are vacant, underutilized, or abandoned industrial and commercial sites where real or perceived environmental contamination is an obstacle to development. Federal initiatives in the 1990s reduced legal liabilities associated with brownfields and provided financial incentives for development initiatives. As brownfields are often located in infill areas, they have advantages over greenfields developments in that much of the supporting infrastructure already exists and they are centrally located. However, the existing infrastructure may be deteriorated and obsolete, and brownfield developments in infill areas may require local as well as areawide transportation improvements. This paper uses a modified impact analysis approach, synthesized from regional transportation modeling and site impact analysis tools, to assess the extrajurisdictional and areawide impacts of clustered brownfield developments. The writers apply this approach to clustered brownfield developments in the City of Pittsburgh. The study results show that the synergistic effects and areawide impacts of clustered brownfield developments may not be adequately captured by traditional site impact studies. This paper is potentially useful for municipal agencies involved in assessing and planning for the transportation improvement needs of clustered brownfield developments.
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| 2. |
- Antoniou, C., et al.
(author)
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Dynamic data-driven local traffic state estimation and prediction
- 2013
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In: Transportation Research Part C. - : Elsevier BV. - 0968-090X .- 1879-2359. ; 34, s. 89-107
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Journal article (peer-reviewed)abstract
- Traffic state prediction is a key problem with considerable implications in modern traffic management. Traffic flow theory has provided significant resources, including models based on traffic flow fundamentals that reflect the underlying phenomena, as well as promote their understanding. They also provide the basis for many traffic simulation models. Speed-density relationships, for example, are routinely used in mesoscopic models. In this paper, an approach for local traffic state estimation and prediction is presented, which exploits available (traffic and other) information and uses data-driven computational approaches. An advantage of the method is its flexibility in incorporating additional explanatory variables. It is also believed that the method is more appropriate for use in the context of mesoscopic traffic simulation models, in place of the traditional speed-density relationships. While these general methods and tools are pre-existing, their application into the specific problem and their integration into the proposed framework for the prediction of traffic state is new. The methodology is illustrated using two freeway data sets from Irvine, CA, and Tel Aviv, Israel. As the proposed models are shown to outperform current state-of-the-art models, they could be valuable when integrated into existing traffic estimation and prediction models.
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| 3. |
- Burghout, Wilco, et al.
(author)
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Hybrid Traffic Simulation Models : Vehicle loading at meso-micro boundaries
- 2019
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In: Transport Simulation. - : CRC Press. - 9781420095098 - 9781439808016 ; , s. 27-42
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Book chapter (other academic/artistic)abstract
- Traffic simulation models, especially microscopic ones, are becoming increasingly popular and are being used to address a wide range of problems, from planning to operations. However, for applications with large-scale networks, microscopic models are impractical because of input data and calibration requirements. Hybrid models that combine simulation models at different levels of detail have the potential to address these practical issues. This chapter presents a framework for implementing meso-micro hybrid models which facilitates a consistent representation of traffic dynamics. Furthermore, the chapter carries out a detailed examination of an important element impacting the consistent representation of traffic dynamics, i.e., the loading of vehicles from the meso- to the micro-model. A new loading method is presented demonstrating a superior performance as compared to existing approaches. The method is useful not only in the context of hybrid models, but also for microscopic models on their own. A case study illustrates the importance of the method in improving the fidelity of both hybrid and pure microscopic models.
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| 4. |
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| 5. |
- Cats, Oded, et al.
(author)
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Bus-Holding Control Strategies Simulation-Based Evaluation and Guidelines for Implementation
- 2012
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In: Transportation Research Record. - : National Academy of Sciences. - 0361-1981 .- 2169-4052. ; :2274, s. 100-108
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Journal article (peer-reviewed)abstract
- Transit operations involve several inherent sources of uncertainty, including dispatch time from the origin terminal, travel time between stops, and dwell time at stops. Bus-holding control strategies are a prominent method applied by transit operators to improve transit performance and level of service. The common practice is to regulate departures from a limited number of stops by holding buses until their scheduled departure time. An analysis of the performance of a high-frequency bus line in Stockholm, Sweden, based on automatic vehicle location data showed that this control strategy was not effective in improving service regularity along the line. The analysis also indicated that drivers adjusted their speed according to performance objectives. Implications of a control strategy that regulates departures from all stops on the basis of the headways of the preceding bus and the following bus were evaluated with Bus Mezzo, a transit operations simulation model. The results suggest that this strategy can improve service performance considerably from both passengers' and operator's perspectives. In addition, the strategy implies cooperative operations, as the decisions of each driver are interdependent with other drivers' decisions, and mutual corrections can be made. Difficulties in realizing the benefits of the proposed strategy in practice, such as dispatching from the origin terminal, driver scheduling, and compliance, are discussed. The implications of several practical considerations are assessed by conducting a sensitivity analysis as part of the preparations for a field experiment designed to test the proposed control strategy.
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| 6. |
- Cats, Oded, et al.
(author)
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Mesoscopic Modeling of Bus Public Transportation
- 2010
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In: Transportation Research Record. - : SAGE Publications. - 0361-1981 .- 2169-4052. ; :2188, s. 9-18
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Journal article (peer-reviewed)abstract
- Analysis of public transport system performance and level of service in urban areas is essential. Dynamic modeling of traffic conditions, passenger demand, and transit operations is important to represent adequately the complexity of and the interactions between these components in modern public transportation systems. This paper presents a transit simulation model designed to support evaluation of operations planning and control, especially in the context of advanced public transportation systems. Unlike most previous efforts in this area, the simulation model is built on a platform of a mesoscopic traffic simulation model, which allows modeling or the operation dynamics of large-scale transit systems, taking into account the main sources of service uncertainty and stochasticity. The capabilities of Mezzo as an evaluation tool of transit operations are demonstrated with an application to a real-world, high-demand bus line in metropolitan Tel Aviv, Israel, under various scenarios. The application shows that important phenomena such as bus bunching are reproduced realistically. A comparison of simulated running times and headway distributions with field data shows the model is capable of replicating observed data.
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| 7. |
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| 8. |
- Cats, Oded, et al.
(author)
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Optimizing the number and location of time point stops
- 2014
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In: Public Transport. - : Springer Science and Business Media LLC. - 1866-749X .- 1613-7159. ; 6:3, s. 215-235
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Journal article (peer-reviewed)abstract
- Public transport service is subject to multiple sources of uncertainty that impact its reliability. Holding control strategies are a common method to prevent the deterioration of service reliability along the route. This paper expands on previous studies by considering the general case of determining both the optimal number and optimal location of the time point stops (TPS) where holding takes place, and assessing their impacts on transit performance using simulation. Holding times are determined based on a real-time headway-based holding strategy designed to improve service regularity by seeking uniform headways along the route. The evaluation of the performance of alternative TPS layouts is simulation-based, using BusMezzo, a transit operations simulation model which models the dynamic performance of bus transit systems. The proposed framework also considers the multiple objectives incorporating passenger and operator points of view. The simulation-based optimization framework was applied in a case study with one of the premium bus lines in Stockholm, Sweden, using two solution methods—greedy and genetic algorithms. A multi-objective evaluation was conducted considering both passenger and operator perspectives. The results demonstrate that transit performance varies considerably with alternative TPS layouts. The best solution obtained by the proposed methodology reduces total weighted passenger journey times and cycle times compared to both the current layout and the case of no holding control. The proposed method could assist transit agencies and operators in evaluating and recommending alternative time point layouts.
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| 9. |
- Fu, Jiali
(author)
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Evaluating and Improving the Transport Efficiency of Logistics Operations
- 2017
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Doctoral thesis (other academic/artistic)abstract
- The thesis focuses on evaluating and improving the transport efficiency of two types of logistics operations in the supply chain.One research area is the production of raw material in construction operations, specifically earthmoving operations. Methods and tools are developed to provide decision support in improving the transport efficiency of earthmoving at the vehicle and the systems levels. Using known road topography and a GPS unit, an optimal control problem is formulated and solved (Paper III) to determine the optimal gear shift sequence and timing in order to improve the transport efficiency at the vehicle level. For decision support at the systems level, a Fleet Performance Simulation (FPS) model is designed (Paper IV) to evaluate the transport efficiency for a given mix of construction vehicles in earthmoving. The FPS system is integrated with an optimization algorithm to solve the optimal fleet composition problem for earthmoving operations (Paper V & VI). Construction operations are dynamic and the environment is changing constantly, which bring difficulties in decision-making. Using GPS data from construction vehicles, a map inference framework (Papers I & II) is developed to automatically extract relevant input to decision support at the vehicle and the systems levels, which include the locations of various workstations, driving time distributions and road networks.The second research area is the transport efficiency of urban distribution system, which is in the final phase of the supply chain. An off-peak delivery pilot project in Stockholm is used as the background, designed to evaluate the potential for commercial vehicles to make use of off-peak hours for goods delivery. The thesis (Paper VII) evaluates the transport efficiency impacts of the off-peak pilot. An evaluation framework is defined where transport efficiency is studied in a number of dimensions. GPS data, fleet management data, and logistic information are used to assess the impacts.
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| 10. |
- Gordon, Jason B., et al.
(author)
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Automated Inference of Linked Transit Journeys in London Using Fare-Transaction and Vehicle Location Data
- 2013
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In: Transportation Research Record. - : SAGE Publications. - 0361-1981 .- 2169-4052. ; :2343, s. 17-24
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Journal article (peer-reviewed)abstract
- Urban public transit providers historically have planned and managed their networks and services with little knowledge of their customers' travel patterns. Although ticket gates and bus fareboxes yield counts of passenger activity in specific stations or vehicles, the relationships between these transactions-the origins, transfers, and destinations of individual passengers-typically have been acquired only through small, costly, and infrequent rider surveys. New methods for inferring the journeys of all riders on a large public transit network have been built on recent work into the use of automated fare collection and vehicle location systems for analysis of passenger behavior. Complete daily sets of data from London's Oyster farecard and the iBus vehicle location system were used to infer boarding and alighting times and locations for individual bus passengers and to infer transfers between passenger trips of various public modes, and origin-destination matrices of linked intermodal transit journeys that include the estimated flows of passengers not using farecards were constructed. The outputs were validated against surveys and traditional origin-destination matrices. The software implementation demonstrated that the procedure is efficient enough to be performed daily, allowing transit providers to observe travel behavior on all services at all times.
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