Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report

Transcription

1 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report Prepared by: The National Center for Smart Growth Research and Education at the University of Maryland* Gerrit Knaap, PhD Director March 2010 *The views expressed do not necessarily represent those of the University of Maryland, the Maryland Department of Transportation, or the State of Maryland.

2 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report March EXECUTIVE SUMMARY The work program under the Memorandum of Understanding between the National Center for Smart Growth at the University of Maryland and the Office of Planning of the Maryland Department of Transportation included the following task: Create feedbacks to a Land Use Model. The purpose of this task was to create the capacity to estimate the development impacts of major transportation investments on land use and development patterns. That task was completed by connecting the Maryland State Transportation Model with the Land Use Assessment Model (LEAM) model developed by the University of Illinois at Urbana-Champaign. LEAM uses input from a regional econometric model to determine land use demand. LEAM then computes local accessibility measures using available networks and derived speeds as a measure of the ease of access to important regional and local attractors. LEAM then uses the speeds derived by the Maryland regional travel demand model to calculate measures of accessibility. The allocation of households derived in LEAM simulations generates demographic and economic data for input into the travel demand model. An exercise using the model demonstrated that the model is sensitive to, and thus can be used to assess the land use impacts of transportation investments. The transportation investments explored in this exercise include investments in: An outer beltway around the Washington metropolitan area; Investments in the Purple and Silver lines in the Washington metropolitan area and the Red line in the Baltimore metropolitan area; A new bridge across the Chesapeake Bay.

3 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report NCSGRE March 2010 Page 2 As a result of these investments more development occurred in the Northern Virginia part and away from the Central Maryland region. More calibration is necessary to confirm these results. But the results demonstrate the potential of using LEAM in combination with the Maryland State Transportation Model to evaluate the land use effects of major state investments in transportation infrastructure. 2 BACKGROUND The National Center for Smart Growth Research and Education (NSCG) at the University of Maryland signed a Memorandum of Understanding with the Maryland Department of Transportation (MDOT) to work jointly on research related to transportation in Maryland. The work plan for 2009, the first year of the contract, contained six research tasks. This report is NCSG s submission for Tasks A4, Creating Feedbacks to a Land Use Model. The original statement of scope for this task was: A report that describes the results of an exercise to identify the impacts of a major transportation investment on land development patterns. The specific transportation investment to be analyzed will be chosen with input from the planning office of MDOT but must be of a sufficient scale as to have statewide development impacts. Potential examples include new bridges across the Potomac or Chesapeake Bay, the expansion of US 301, or the widening of MD Route 32. The purpose of this task was to create the capacity to estimate the development impacts of major transportation investments on land use and development patterns. At present, development impacts are often estimated using delphi techniques where land use expert provide and exchange opinions on the effects of transportation investments on land development. After several iterations, a consensus forecast is developed that can be used in an Environmental Impact Statement. An integrated transportation-land use model enables policy makers to explore land development impacts without using delphi techniques or convening an expert panel. An integrated transportation-land use model also permits the rapid experimentation of alternative investments under differing assumptions of development sensitivity to increases in accessibility.

4 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report NCSGRE March 2010 Page 3 To build this capacity we first had to develop econometric, transportation, and land use models. These were developed with funding provided by a variety of sources including the Maryland State Highway Administration. This report focuses on the development of an integrated transportation-land use model and contains three parts. The rest of this report has three sections: Section 2, Modeling Framework: Description of the overall modeling framework. Section 3, A Transportation Investment Exercise: Description of the results of a transportation investment exercise. Section 4, Conclusion and Recommendations for Future Work 3 MODELING FRAMEWORK The modeling system is illustrated in Figure 1 below. As shown, the modeling system includes a national econometric model, a land use model, a transportation model, and several impact models. A model exercise begins with a national economic forecast of employment, output, and wages of 95 sectors of the US economy. The output of this model is disaggregated to the state level where it is fed into the land use model. The land use model then allocates jobs by industrial sector and household by income levels into State Modeling Zones (SMZs). Jobs and households at the SMZ level are fed into the state transportation model which then forecasts traffic for each link in the network. The outputs of the transportation and land use models are fed into impact models that identify the impacts of each scenario on public expenditures, nutrient loading, and residential energy use, and more.

5 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report NCSGRE March 2010 Page 4 Figure 1. Modeling Framework Figure Figure 2. Econometric Model Framework 3.1 THE ECONOMIC MODEL The Economic Model consists of two models developed by INFORUM, an econometrics research center affiliated with the UMD economics department. Specifically, the economic model includes the Long Range Interindustry Forecasting Tool (LIFT) model, a national computable general equilibrium model, and the State Employment Modeling System (STEMS), a model that disaggregates the results from the LIFT model into employment, output, and wage forecasts for individual states. Elements of the LIFT model are illustrated in Figure 3.2 THE LAND USE MODELS The modeling framework includes two models as shown in Figure 3. First, the Center has partnered with the Land Use Evolution and Impact Assessment Modeling (LEAM) Laboratory at the University of Illinois to develop a bottom-up land use model. LEAM is a dynamic visual decision support tool that uses a Cellular Automata (CA) approach tightly coupled with an open architecture for model development and high-performance computing capabilities for simulating land-use transformation. See Appendix A and for more information. Second, as part of the development of the statewide transportation model the NCSG, Inforum, and Dr. Thomas Hammer developed a top-down land use model. The model takes inputs from Inforum s national and state econometric models and disaggregates jobs and households to the county and state modeling zone levels based on regression analysis of historic job and household distribution patterns and gravity relationships. Because the model includes parameters that capture development potential and travel times between modeling regions the model is able to interface interactively with the transportation model to capture transportation-land use interactions.

6 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report NCSGRE March 2010 Page 5 Figure 3. Land Use Models Figure 4. Transportation Model Framework 3.3 THE TRANSPORTATION MODEL The Transportation Model includes three parts: (1) a passenger model at the Transportation Analysis Zone levels for the Baltimore and Washington metropolitan areas; (2) a statewide passenger model at the state modeling zone (SMZ) that includes the state of Maryland and surrounding counties; and (3) a freight model at the Freight Analysis Zone (FAF) level that includes most of the Eastern Seaboard states. The model is illustrated in Figure 2. The person travel model estimates trip making within and through Maryland made by residents of and visitors to the state. The transportation component includes a series of separate but compatible models. These include a travel model for statewide residents that predicts all travel within and through Maryland, a mode choice model, and an external trip model. Visiting travelers into Maryland are accounted for in the external trip model. The travel model at the statewide level is based upon the quick response modeling framework outlined in NCHRP Report 187 and subsequently updated in NCHRP Report 365. The data on trip making from these reports are modified based upon data from the Census Journey to Work and Maryland element of the National Household Travel Survey. This model pivots off of the statewide flows by trip purpose, although sensitive to the Baltimore and Washington mode shares (by virtue of replacing the statewide model estimates with those from their respective models). The freight model functions as an analog to the person travel model but uses different data sources and model structures. County-to-county flows from the FAF are used in the upper level of the model to portray freight moving within and through the modeled area.

7 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report NCSGRE March 2010 Page 6 4 A TRANSPORTATION INVESTMENT EXERCISE Year 1 of the scope of work for the project funded by the Maryland Department of Transportation and the University of Maryland Office of Research included two tasks: (1) Linking the LEAM land use model to the transportation model; and (2) analyzing the effects of major transportation investments in urban development patterns. Task 1 began with the integration of LEAM with the statewide transportation model. LEAM uses input from the regional econometric model (STEMS) to determine land use demand. LEAM then computes local accessibility measures using available networks and derived speeds as a measure of the ease of access to important regional and local attractors. LEAM then uses the speeds derived by the Maryland regional travel demand model to calculate measures of accessibility. The allocation of households derived in LEAM simulations generates demographic and economic data for input into the travel demand model. A fully integrated run follows the patterns described in Figure 5 at 5 year intervals. Figure 5. Feedback between coupled Statewide Transportation Model and LEAM systems. Trip Generation Trip Distribution Household location Employment location Land Use Change Modal Split Traffic Assignment Speed on Links Travel Demand Model É SMZ Analysis Feedback Accessiblity Job Centers Transportation Bussiness Centers Shopping Centers É LEAM Task 2 began with the development of a base case scenario using 2040 forecasts from the LIFT model and feeding the control totals at the regional level into LEAM. LEAM in turn produces a base case land development scenario called the Business as Usual (BAU) scenario, as shown in Figure 6. In Figure 6, most of the development in the model region occurs at the fringes of the Baltimore- Washington metropolitan areas. Areas highlighted in darker blues illustrate intense development in Howard County between Baltimore and Washington.

8 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report Figure 6 Business As Usual Scenario NCSGRE March 2010 Page 7

9 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report NCSGRE March 2010 Page 8 Figure 7. Transportation Investments Figure 7 illustrates the introduction of several major transportation investments. These include: an outer beltway around the Washington metropolitan area; the Silver Line extension of Metro to Dulles Airport, the Purple Line extension from New Carrolton to Bethesda; the Red Line extension of the Baltimore light rail system; and a new bridge extending across the Chesapeake Bay. The effects of these investments are illustrated in Figure 8 and is called the Transportation Investment (TI) Scenario.

10 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report NCSGRE March 2010 Page 9 Figure 8: Transportation Investment Scenario Figure 9: Effects of Transportation Investments on Development Figure 9 illustrates the difference between the BAU scenario and the TI scenario. As shown in Figure 9, the major difference between the scenarios involves the general location of development. In figure 9, red and yellow colors indicate less development in the TI scenario and blue colors indicate more development in the TI scenario. In the TI scenario, less development occurs in the southern Baltimore/northern Washington regions of the modeling areas and more development occurs in Northern Virginia. The likely cause of this shift in

11 Linking the Transportation Model to the LEAM Land Use Model: Year 1 Final Report NCSGRE March 2010 Page 10 development is the greater general accessibility in the entire region that stems from the set of transportation investments and the greater draw of employment opportunities in Northern Virginia. Interestingly, the model projects very little additional development on the Eastern Shore as a result of the constriction of a new bridge. We suspect this is because of the lack of employment opportunities. The model is not well suited to addressing second homes. Also somewhat surprisingly, the model projects very little development around the new light rail transit stations in either the Baltimore or Washington areas. This is perhaps because the model does not adequately capture the potential development impacts of transit accessibility. These are both issues to explore in the subsequent development of the models. 5 CONCLUSION AND RECOMMENDATIONS FOR FUTURE WORK Year 1 of the work programs of the UTC, MDOT, and SHA contracts produced substantial progress in model development. This included econometric, land use, transportation, and environmental impact models. The focus of the work supported by the MDOT and UTC and reported here was on the development of the land use model and linking the land use and transportation models. That task was fully completed. No model, or set of models, however, is generally satisfactory in their first phase of development. Work do date demonstrates that the LEAM land use model is sensitive to transportation parameters and model output reflects the impact of changes in accessibility that stem from major investments in transportation infrastructure. Additional calibration is needed, however, before the model is suitable for use in project or corridor analyses.