Browsing by Subject "Microsimulation"

Now showing 1 - 10 of 10
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    The case for microsimulation frameworks for integrated urban models
    (Journal of Transport and Land Use, 2018) Miller, Eric
    The primary objective of this paper is to "make the case" for adoption of microsimulation frameworks for development of integrated urban models. Similar to the case of activity-based travel models, microsimulation in integrated urban models enables such models to deal better with: heterogeneity and non-linearity in behavior; identification of the detailed spatial and socioeconomic distribution of impacts, benefits and costs; tracing complex interactions across agents and over time; providing support for modelling memory, learning and adaptation among agents; computational efficiency; and emergent behavior. The paper discusses strengths, weaknesses and challenges in microsimulating urban regions, including the extent to which microsimulation models are still subject to Lee’s famous "seven sins of large-scale modelling," as well as the extent to which they may help alleviate or reduce these sins in operational models. The paper concludes with a very brief discussion of future prospects for such models.
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    An integrated microsimulation approach to land-use and mobility modeling
    (Journal of Transport and Land Use, 2018) Zhu, Yi; Diao, Mi; Ferreira, Joseph Jr.; Zegras, P. Christopher
    This paper presents an overview of the design and status of a new type of land-use simulation module integrated into SimMobility, an agent-based microsimulation platform. The module, SimMobility Long-Term (LT), is designed to simulate how the interrelations between the transportation and land-use systems manifest themselves in the housing and commercial real estate markets, household and firm location choices, school and workplace choices, and vehicle ownership choices. At the heart of the LT simulator is a housing market module simulating daily dynamics in the residential housing market that (a) “awakens” households that begin searching for new housing; (b) accounts for eligibility, affordability, and screening constraints; (c) constructs plausible choice sets; (d) simulates daily housing market bidding; and (e) represents developer behavior regarding when, where, what type, and how much built space to construct, taking into account market cycle and uncertainty. The LT simulator and SimMobility’s activity-based, mid-term (MT) simulator are integrated in that the agents in the LT module (e.g., individuals in households) are the same agents simulated in the MT module (e.g., activity participation and trip-making), and agents’ simulated behaviors in the MT module provide measures of (utility-based) accessibility that figure into relevant decisions in the LT simulator. This paper describes the SimMobility model and the LT framework, presents estimation results for two component models of the housing supply side, and demonstrates the use of the simulator by comparing housing market outcomes with and without the introduction of one year’s worth of supply of new public housing. Overall, the LT simulator represents an effort to advance urban system modelling by explicitly simulating the dynamic interactions of disaggregated agents in real estate markets and encapsulating the information of agents’ daily activity participation in their long-term mobility-relevant choices.
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    Land use–transport interaction modeling: A review of the literature and future research directions
    (Journal of Transport and Land Use, 2015) Acheampong, Ransford A.; Silva, Elisabete A.
    The aim of this review paper is to provide comprehensive and up-to-date material for both researchers and practitioners interested in land-use-transport interaction (LUTI) modeling. The paper brings together some 60 years of published research on the subject. The review discusses the dominant theoretical and conceptual propositions underpinning research in the field and the existing operational LUTI modeling frameworks as well as the modeling methodologies that have been applied over the years. On the basis of these, the paper discusses the challenges, on-going progress and future research directions around the following thematic areas: 1) the challenges imposed by disaggregation—data availability, computation time, stochastic variation and output uncertainty; 2) the challenges of and progress in integrating activity-based travel demand models into LUTI models; 3) the quest for a satisfactory measure of accessibility; and 4) progress and challenges toward integrating the environment into LUTI models.
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    Microsimulating parcel-level land use and activity-based travel: Development of a prototype application in San Francisco
    (Journal of Transport and Land Use, 2010) Waddell, Paul; Wang, Liming; Charlton, Billy; Olsen, Aksel
    This paper develops a prototype of an integrated microsimulation model system combining land use at a parcel level with activity-based travel in San Francisco, California. The paper describes the motivation for the model system, its design, data development, and preliminary application and testing. The land use model is implemented using UrbanSim and the Open Platform for Urban Simulation (OPUS), using parcels and buildings rather than zones or grid cells as spatial units of analysis. Measures of accessibility are derived from the San Francisco SF-CHAMP activity-based travel model, and the predicted locations of households and business establishments are used to update the micro-level inputs needed for the activity-based travel model. Data used in the model include business establishments linked to parcels over several years, and a panel of parcels that allow modeling of parcel development over time. This paper describes several advances that have not been previously integrated in an operational model system, including the use of parcels and buildings as units of location for consumers and developers of real estate, the use of business establishments to represent economic activity, and the interfacing of this microsimulation land use model with a microsimulation activity-based travel model. Computational performance and development effort were found to be modest, with land use model run times averaging one minute per year on a current desktop computer, and two to three minutes on a current laptop. By contrast, long run times of the travel model suggest that there may be a need to reconsider the level of complexity in the travel model for an integrated land use and transportation model system application to be broadly usable. The land use model is currently in refinement, being used to identify input data and model specification adjustments needed in order to bring it into operational use, which is planned over the next several months.
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    Multi-level urban models: Integration across space, time and policies
    (Journal of Transport and Land Use, 2018) Wegener, Michael; Spiekermann, Klaus
    Urban and regional models have been developed for different policy fields at different levels of spatial and temporal resolution. But it has become apparent that policies interact across space and time and need to be modelled together. The first urban and regional models were aggregate in space and comparative-static in time. More recently, new data sources and computing techniques have stimulated ever more disaggregation in space and time culminating in agent-based, activity-based microsimulation despite its significant even larger data needs, computing requirements and theoretical problems. This paper argues for models that are instead multi-level and multi-scale in space, time and subsystems. This paper starts with a brief history of urban models and the experience of the authors with the highly integrated urban microsimulation model ILUMASS. Based on this experience, it discusses the benefits and pitfalls of microsimulation and proposes a three-level model system of spatial development, ranging from the European to the local level. The paper closes with new challenges for urban models posed by climate change, energy scarcity, new social problems and new technologies and argues that they make multi-level, multi-scale models even more important and illustrates this by ongoing work with the multi-level model for cities in the Ruhr.
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    Oregon's Transportation and Land Use Model Integration Program: A retrospective
    (Journal of Transport and Land Use, 2018) Donnelly, Rick; Upton, William J.; Knudson, Becky
    An ambitious and innovative integrated land use-transport modeling system has been developed in Oregon over the past two decades. This work, completed under the Transportation and Land Use Model Integration Program (TLUMIP), included the development of two generations of models and the data required to build and use them and spawned the development of two others that have continued independently. An outreach program and collaborative development of freight data and forecasts were also included, as well as system testing and applications. A brief description of the motivation behind TLUMIP and the resulting modeling systems are presented. Perhaps more interesting is the story behind the models, describing several major model design, institutional, and methodology issues that were overcome. Using an integrated model in practice also entailed addressing a wider range of analytical requirements and stakeholder expectations about usability, accuracy, and extensibility than typically considered in academic pursuits. The key lessons learned through development and use of the models are discussed, with the hope that they will inform the development of similar large-scale modeling systems.
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    Testing microsimulation uncertainty of the parcel-based space development module of the Baltimore PECAS Demo Model
    (Journal of Transport and Land Use, 2020) Wang, Wanle; Zhong, Ming; Zhang, Yiming; Li, Yaqiu; Ma, Xiaofeng; Hunt, John Douglas; Abraham, John Edward
    A precise and stable microsimulation space development module is fundamental for supporting various policy decision-making exercises related to land development. This paper studies the dynamics or uncertainty of outputs of the parcel-based space development module of an integrated land-use and transport forecasting model—the Baltimore PECAS Demo Model. It is tested with two sub-studies: (1) running the model three times over the entire planning window from 2000 to 2030; and (2) running the model 30 times just one year ahead from 2000 to 2001. The outputs obtained are used to analyze such dynamics or uncertainty. Study results from the first sub-study show that, in general, the system is stable and consistent over runs and time, as supported by a set of paired t-tests. However, the coefficient of variation (COV) measuring the variation of estimated space quantity by category over four cross-section years indicates that the differences among runs are increasing over time through the planning window. The COV test over the second sub-study indicates the estimated space quantity is stable for most of the zones, except for a small portion of zones with a small space quantity.
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    Toward implementation of max-pressure control on Minnesota roads: Phase 2
    (Minnesota Department of Transportation, 2024-10) Stern, Raphael; Levin, Michael W.; Kiani, Amirhossein
    Max-pressure (MP) traffic signal control is a new and innovative control algorithm that uses upstream and downstream vehicle counts to determine signal timing that maximizes throughput. While this method has been extensively tested in simulation, it has not yet been tested on actual traffic signals in the US. To close this gap, this report presents the results of the development of a hardware-in-the-loop traffic signal testbed where microsimulation is used to simulate realistic traffic conditions, and the MP algorithm is used to control the signal display using a traffic controller (Q-Free MaxTime controller). The hardware-in-the-loop results demonstrate that MP can be safely deployed on North American traffic signal control hardware.
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    Traffic noise feedback in agent-based Integrated Land-Use/Transport Models
    (Journal of Transport and Land Use, 2021) Kuehnel, Nico; Ziemke, Dominik; Moeckel, Rolf
    Road traffic is a common source of negative environmental externalities such as noise and air pollution. While existing transport models are capable of accurately representing environmental stressors of road traffic, this is less true for integrated land-use/transport models. So-called land-use-transport-environment models aim to integrate environmental impacts. However, the environmental implications are often analyzed as an output of the model only, even though research suggests that the environment itself can have an impact on land use. The few existing models that actually introduce a feedback between land-use and environment fall back on aggregated zonal values. This paper presents a proof of concept for an integrated, microscopic and agent-based approach for a feedback loop between transport-related noise emissions and land-use. The results show that the microscopic link between the submodels is operational and fine-grained analysis by different types of agents is possible. It is shown that high-income households react differently to noise exposure when compared low-income households. The presented approach opens new possibilities for analyzing and understanding noise abatement policies as well as issues of environmental equity. The methodology can be transferred to include air pollutant emissions in the future.
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    Trends in integrated land use/transport modeling: An evaluation of the state of the art
    (Journal of Transport and Land Use, 2018) Moeckel, Rolf; Llorca Garcia, Carlos; Moreno Chou, Ana T.; Okrah, Matthew Bediako
    Integrated land-use/transport models have five decades of history of both widely recognized successful implementations and implementations that remained far behind their originally stated goals. This paper summarizes the state of the art of integrated land-use/transport modeling and reports on findings from the Symposium for the Integration of Land-Use and Transport Models in Raitenhaslach, which is near Munich, in 2016. From these sources, the paper identifies major challenges in integrated land-use/transport modeling and proposes paths that support successful implementations. Particular attention is given to the coordination of short- and long-term decisions, the technical integration of models, microscopic versus macroscopic frameworks and appropriate levels of model complexity. The paper concludes with five themes that require further research to ensure that integrated land-use/transport models will keep up with modeling needs in the future.