FHWA Scenario Planning Guidebook
Phase 2. Where Are We Now?
Establish a baseline analysis. Identify factors and trends that affect the state, community, region, or study area.
Phase 2 focuses on collecting data to describe the state, community, region, or study area. Data can include information about the transportation system, demographics, environmental resources and constraints, as well as land-use patterns as they relate to transportation. Obtaining baseline data is important for several reasons. First, data will be compiled into a baseline analysis to compare alternative scenario outcomes with current conditions. Baseline data can also help agencies to tailor scenario analysis tools—if such tools will be used in the effort—to reflect specific regional conditions. A range of planning partners and the public can be involved during Phase 2 to help identify and obtain baseline data.
Overall, gathering baseline data can help to answer the following questions:
- What is the current supply and demand for transportation?
- What geographic, environmental, or other constraints exist that might limit future population growth, transportation network expansion, residential development, or other changes?
- What other factors (e.g., desire for walkability or compact growth, energy use) currently affect supply, demand, and constraints?
- Given current trends, what could the future look like?
There are several steps to Phase 2. Agencies should:
Each step is listed on the next page, along with associated key questions that agencies can consider. Some steps provide examples of additional issues or questions for further consideration.
Involving Planning Partners in Gathering Baseline Data
In 2007, the MPO for the Nashville, Tennessee, region began the Tri-County Transportation and Land Use Study to explore growth options for three of its member counties.* Results of the study will be used to generate ideas for the regional transportation plan.
The effort has involved conducting public visioning workshops to identify regional growth goals and developing several scenarios to test growth alternatives. The MPO is in the process of building a growth assessment model to assess completed scenarios.
To gather data on the suitability and desirability of buildable areas for this effort, the MPO met with focus groups to assess priority locations for development. Focus group members included planning policy-makers, real estate agents, developers, and utility departments. Qualitative information gathered from the focus groups was supplemented with quantitative data obtained from tax assessments and censuses.
*For more information about the Nashville MPO, see www.nashvillempo.org/.
Step 2.1: Characterize the supply, suitability, and demand for transportation and land use as it relates to the transportation system.
- Inventory and compile data resources describing current conditions. Relevant data can be obtained from many sources, including zoning regulations, design manuals, adopted plans, traffic data and existing models, census information, nationally or regionally available datasets, and satellite and remote sensing imagery. In some cases, substantial field work might be required to compile and/or refine data.
- Characterize current development patterns (e.g., suburban, urban, single family, mixed use).
- Ensure that data are in an appropriate format. For example, the transportation network might need to be inventoried. Zoning and land use regulations might need to be simplified into representative place types in order to facilitate geospatial modeling (which could occur in Phase 4 or 5). Traffic-count data might need to be analyzed to represent level of service and available capacity. Geological, topographical, and environmental data might need to be reviewed and analyzed to identify areas that are suitable for development.
- Consider how qualitative data compilation and analysis might be used during Step 2.1 and later phases of the process.
- Build the agency's data and/or geospatial capacity if necessary. Quantitative data, particularly data that are in a geographic information system (GIS) format, are often at the heart of scenario planning analyses. GIS data are often used to build scenarios (in Phases 3 and/or 4) or to allow stakeholders to more easily visualize scenario impacts (in Phases 3, 5, and/or 6).
- Identify relevant organizations, such as a statewide GIS consortium, which might have applicable data and could share this information. This step might be particularly important for smaller agencies that do not have access to extensive data.
- Build coalitions with technical or data staff in the agency; ensure that these staff members have opportunities to participate and weigh in on the baseline analysis as well as activities in later phases of the scenario planning effort.
- Consider what analysis tools might be used to assess scenario impacts. Scenario assessment occurs in Phase 4; details on types and examples of analysis tools are provided in Phase 4 of the guidebook. During Phase 2, data should be collected in formats that are appropriate for use in the chosen analysis tool(s). Remember that some analysis tools might focus more on qualitative comparison than on quantitative inputs. During this step, address the following questions:
- How will data be analyzed to compile a baseline analysis?
- Will baseline data be entered into a travel demand model or analysis tool?
- What format should the data take to support this integration?
- What actions should occur to reformat data if necessary?
- Obtain data on current conditions. Relevant data can be obtained from many sources, including zoning regulations, design manuals, adopted plans, traffic data, existing models, census information, nationally or regionally available datasets, or satellite and remote sensing imagery.
- Identify recent historical trends related to transportation and development. Address the following questions:
- What is the historical demand for transportation and land use (e.g., as identified through use of a travel demand survey or projected employment/ population growth)?
- What environmental, demographic, or market trends have influenced the demand for various transportation facilities, modes, or alignments?
- How have environmental, demographic, or market trends influenced the demand for development or growth?
- How have transportation policies affected transportation demand and/or the suitability of land for development?
- Is demand likely to change? If so, by how much?
- Verify the accuracy of supply, suitability, and demand characterizations by validating data with stakeholders. Revise as necessary. Inaccurate or invalid data can affect the success of the scenario planning process. Participants are less likely to trust the scenario planning process if they do not believe that the data are accurate and valid.
- Consider use of visualization tools that can provide examples of existing and potential future community types to stakeholders. Examples of visualization tools are provided in Phase 4 of the guidebook.
- Consider how to engage stakeholders to validate characterizations (e.g., through focus groups, polling, and visual preference surveys).
Building a Land Suitability Map
As part of the Tri-County Transportation and Land Use Study, the MPO for the Nashville, Tennessee, region used several modeling tools to evaluate the region's potential for growth.*
As a first step, the Nashville MPO created an aggregate land suitability map that evaluated land parcels on their proximity to several factors, such as water/sewer infrastructure, network roads, major intersections, parks and other recreational opportunities, transit stations, and environmental features (e.g., floodplains, rare species). The aggregate map will be used to assess how the region is growing and could grow in the future.
The aggregate map is shown below. Red coloring indicates the parcel(s) with highest suitability for development. Blue coloring indicates the parcel(s) with the lowest suitability.
Next, the MPO assessed demand for development. Population and employment growth were projected to 2035 for residential and nonresidential areas at the household and square-footage levels. Distribution of future growth was plotted on a map, using inputs from land suitability analyses.
The results of the land suitability and demand analysis will be used to build scenarios that explore growth options for the MPO's member counties.
*For more information on the study, see www.nashvillempo.org/regional_plan/land_use/study_tri_county.aspx.
Step 2.2: Consider how trends could impact these factors in the future.
- Consider and evaluate local trends or factors that impact supply, suitability, and demand characterizations.
- Consider how factors and trends could change over time.
- Identify strategies to obtain information on relevant local trends and issues, such as obtaining data on relevant topics from partner organizations, conducting interviews with key stakeholders, or convening focus groups to acquire additional information.
- Consider what external trends and factors occurring outside the state, community, region, or study area might impact transportation and land use.
- Consider how factors and trends could change over time.
- Identify strategies to obtain information on relevant external trends and issues, such as obtaining data on relevant topics from partner organizations (e.g., statewide or regional data clearinghouses), conducting interviews with key stakeholders, or convening focus groups to acquire additional information.
- Include planning partners and the public in exploring how supply, suitability, and demand characterizations could change over time.
Phase 2 Outputs
Possible outputs of Phase 2 are analyses of baseline data that describe the supply, suitability, and demand of transportation and transportation-related land use in the region. The products that document the baseline conditions could include an inventory of transportation systems, a land suitability analysis, or evaluations of historical population growth or land use. Information from the baseline assessment will be used later in the scenario planning process to build and assess both baseline and alternative scenarios.