Browsing by Subject "UrbanSim"

Now showing 1 - 5 of 5
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    Disaggregate models with aggregate data: Two UrbanSim applications
    (Journal of Transport and Land Use, 2010) Patterson, Zachary; Kryvobokov, Marko; Marchal, Fabrice; Bierlaire, Michel
    UrbanSim has significant data requirements. In particular, it requires disaggregate data (traditionally at the 150 meter by 150 meter gridcell level) for employment, households, and buildings. While such data are not always easily available, most regions have readily available data in a more aggregate form, often at the level of traffic analysis zone (TAZ) or other municipal divisions. This paper describes two UrbanSim applications for the cities of Brussels, Belgium and Lyon, France that adopted different approaches of using aggregate data. In Brussels, aggregate zonal data were disaggregated to the gridcell level. In the Lyon application, the zone was used as the unit of analysis and as such, each zone corresponds to one gridcell. The objectives of this paper are: 1) establish whether an UrbanSim model can be developed using aggregate data; 2) describe two different approaches to using aggregate data with UrbanSim and evaluate; and 3) evaluate the advantages and disadvantages of using aggregate data, as well as the two different approaches described. In doing so, it advances knowledge in the field of transportation and land use modeling by helping modelers evaluate the use of an increasingly popular integrated transportation land use modeling option. Several conclusions flow from this work. First, aggregate data can be used to develop UrbanSim models. Second, only a limited amount of disaggregate information can be drawn from aggregate data. In the context of UrbanSim, this is manifested in models with relatively few variables and dubious simulation results—in other words, while it is possible to develop an UrbanSim application with aggregate data, it should not be used for applied analysis. Finally, the development of such models can be a relatively low-cost exercise to gain familiarity with UrbanSim’s functioning and data requirements. As a result, it can also be seen as an important first step to developing or evaluating UrbanSim for application in a new region.
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    Land use uncertainty in transportation forecast
    (Journal of Transport and Land Use, 2021) Ševčíková, Hana; Nichols, Brice
    Using an integrated land use and travel model system implemented for the Puget Sound region in Washington state, a Bayesian Melding technique is applied to represent variations in land use outcomes, and is propagated into travel choices across a multi-year agent-based simulation. A scenario is considered where zoned capacity is increased around light rail stations. Samples are drawn from the posterior distribution of households to generate travel model inputs. They allow for propagation of land use uncertainty into travel choices, which are themselves assessed for uncertainty by comparing against observed data. Resulting travel measures of zonal vehicle miles traveled (VMT) per capita and light rail station boardings indicate the importance of comparing distributions rather than point forecasts. Results suggest decreased VMT per capita in zones near light rail stations and increased boardings at certain stations with existing development, and less significant impacts around stations with lower initial development capacity. In many cases, individual point level comparisons of scenarios would lead to very different conclusions. Altogether, this finding adds to a line of work demonstrating the policy value of incorporating uncertainty in integrated models and provides a method for assessing these variations in a systematic way.
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    Land use-transportation modeling with UrbanSim: Experiences and progress
    (Journal of Transport and Land Use, 2010) Felsenstein, Daniel; Axhausen, Kay; Waddell, Paul
    As an open source and modular software system using highly disaggregated data for dynamic simulation, UrbanSim has been instrumental in making integrated land-use transportation modeling accessible beyond the bespoke models that characterized earlier generations. The UrbanSim model and the collaborative OPUS framework (Open Platform for Urban Simulation) that it has spawned have stimulated much original progress in this field. The object of this thematic issue of the Journal of Transport and Land Use is to report on this work and to illustrate the various ways UrbanSim has been adapted. However, this special issue is more than just a collection of progress reports. A central theme running through all the papers is that integrated land use-transportation modeling in Europe presents a series of challenges and demands not necessarily present in the United States context in which UrbanSim was developed. Thus, while the UrbanSim system can be technically adapted to European studies given the data and resources, the prevailing land-use transportation environment in Europe differs from the United States.
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    Modelling hedonic residential rents for land use and transport simulation while considering spatial effects
    (Journal of Transport and Land Use, 2010) Löchl, Michael; Axhausen, Kay
    The application of UrbanSim requires land or real estate price data for the study area. These can be difficult to obtain, particularly when tax assessor data and data from commercial sources are unavailable. The article discusses an alternative method of data acquisition and applies hedonic modeling techniques in order to generate the required data. Many studies have highlighted that ordinary least square (OLS) regression approaches lack the ability to consider spatial dependency and spatial heterogeneity, consequently leading to biased and inefficient estimations. Therefore, a comprehensive data set is used for modeling residential asking rents by applying and comparing OLS, spatial autoregressive, and geographically weighted regression (GWR) techniques. The latter technique performed best with regard to model fit, but the issue of correlated coefficients favored a spatial simultaneous autoregressive model. Overall, the article reveals that when housing markets are a particular concern in UrbanSim applications, significant efforts are needed for the price data generation and modeling. The study concludes with further development potentials for UrbanSim.
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    Simultaneous modeling of developer behavior and land prices in UrbanSim
    (Journal of Transport and Land Use, 2010) Felsenstein, Daniel; Ashbel, Eyal
    A strong inter-dependence exists between the decision to develop land and the expected returns to be gained from that development. Current practice in UrbanSim modeling treats developer behavior and the emergence of land prices as independent processes. This assumes that land prices are exogenous to the interaction between buyers and sellers—an assumption that is difficult to sustain in urban economics and real estate research. This paper presents an attempt to model the two processes as occurring simultaneously. Using the UrbanSim model for metropolitan Tel Aviv, we compare the results of forecasts for densities (residential and non-residential) and land values for the period 2001–2020. Our results show that simultaneous estimation tends to produce more accentuated outcomes and volatile trends. The validity of these results and the implications of this approach in the wider context of land use modeling are discussed.