APPENDIX I: Traffic Forecasting Model and Assumptions

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1 APPENDIX I: Traffic Forecasting Model and Assumptions Appendix I reports on the assumptions and traffic model specifications that were developed to support the Reaffirmation of the 2040 Long Range Plan. Among the main tasks accomplished in updating the urban travel demand model for the urban area of Rochester were to refine the Traffic Analysis Zone network to provide greater specificity in areas on the fringe of the Rochester, to incorporate the results of refinement of the 2040 population and employment forecasts in the model, and to revise highway network capacities and speed assignments as needed to incorporate any changes made during recent subarea studies. Preparation of the regional (vs urban) non-model generated traffic forecasts are based primarily on study of historic traffic volume trends for county and state roads along with review and incorporation of information from MNDOT s most recent trunk highway forecasts. In the regional study area the focus is on the state and county highway network, since these roads carry the vast majority of regional intercity traffic and there is a sufficient database of historic traffic counts and road characteristics on which future forecasts can be built. Urban Area Travel Demand Model Traffic forecasting for the Urban Study area focuses on roadways whose function is anticipated to be broader than strictly serving property access needs. All non-local State, County and city streets classified as arterial and collector roads are included on the model network. In developing the urban area travel demand model, a series of steps were completed to generate the input information needed to run the model. These included: Update Traffic Analysis Zone Boundaries Define Base Year and Horizon Year Land Use Forecasts Assign Land Use to Traffic Analysis Zones Review and refine, if needed, Trip Generation categories and trip rates Refine traffic model highway network, including adding or deleting links and confirming capacity and typical operating speeds of links in the network Calibrate the traffic model F - 1

2 Traffic Analysis Zones Figure I-1 highlights the Traffic Analysis Zone network for the Rochester urban area. It contains a total of 466 zones, with smaller zones resulting in a more finely grained network in the urban core and larger zones on the outer fringe, where development and traffic generation is less concentrated. Figure I-1 F - 2

3 Land Use Forecasts For purposes of running the traffic model, employment and population projections are converted into equivalent land use units to serve as input to the Horizon Year land use for the traffic forecasting element of the model. The Base Year uses current land use selected for a specific year. Chapter 10 reported on projected 2040 population forecasts and employment forecasts. Population forecasts are used to estimate growth in housing units by type, school enrollments and park needs. Employment forecasts are used to estimate the square footage of new development including retail, office, health care and industrial development. Table I-1 summarizes projected levels of growth by traffic model land use category. F - 3

4 Assignment of Land Use to Traffic Analysis Zones Following estimation of total growth in terms of housing units and square footage of nonresidential development, development must be allocated spatially across the urban study area. Figures I-3 through I-6 on the following four pages highlight the assumptions that were made regarding the distribution of new development for the 2040 forecast scenario. These assumptions give preference to undeveloped housing or non-residential acreage in General Development Plans that have been approved but not built out as the highest priority areas for future development, with secondary priority assigned to areas which either have sewer and water service available and a high level of major road accessibility. Figure I-7 then provides an overview of the 2040 traffic project volumes. For the downtown Rochester area, assumptions regarding future land use were derived from the Rochester Downtown Master Plan as approved in mid This was a major study sponsored by the City of Rochester, the Mayo Medical Center, the University of Minnesota-Rochester, the Rochester Area Chamber of Commerce and the Rochester Area Foundation. Based on the initial land use visioning completed for this project, a land use scenario, illustrated in Figure I-2 i, was developed and used to develop model inputs related to the distribution of new housing and nonresidential use in downtown Rochester. EDUCATION/ RESEARCH DISTRICT MAYO Figure I-2 MAIN STREET MIXED USE BROADWAY AVE ARTS CULTURAL DISTRICT UMR F - 4

5 Figure I-3 F - 5

6 Figure I-4 F - 6

7 Figure I-5 F - 7

8 Figure I-6 F - 8

9 Figure I-7: Travel Demand Model Highway Network i Figure 4-10 from Rochester Downtown Master Plan, June 2010 Open House #3 Presentation, accessed online at F - 9