Step 4: Future Conditions

Future Travel Demand Determination

Future travel demand is determined based on an evaluation of the adopted comprehensive plan land uses assumptions and population and employment forecasts. Future travel demand should be determined for all elements of the transportation system that were documented in the existing conditions for the jurisdiction (e.g., roadway, transit, bicycle, pedestrian, freight, rail, air, pipeline, and marine) as appropriate for the jurisdiction and scaled to community size. The impact of anticipated changes in land use and/or the addition of significant traffic generators should consider all travel modes.

 Shall

At a minimum, this step shall include:

• Population changes through the planning horizon – Portland State University's Population Research Center provides population data, information, research, and analysis for Oregon and its communities.
• Employment changes through the planning horizon – Most larger communities have completed economic opportunity analyses. Some regions have also completed regional economic opportunity analyses. Some of those documents, depending on the magnitude of work completed, include employment forecast data. Otherwise, the U.S. Census and the Oregon Employment Department can provide information on employment growth.
• Projected changes in population and employment shall be distributed throughout the urban growth boundary consistent with the acknowledged comprehensive plan. The changes in population and employment shall be converted into personal travel on the transportation system and then assigned as pedestrian, bicycle, transit, and motor vehicle volumes. The additional volumes shall be applied to current volumes to produce a forecast of future transportation system conditions. The forecasting methodology should be appropriate to the questions being asked and the complexity of the issues related to the transportation system. There are four levels of methodology, ranging from simple, straightforward trending analyses to more complex and sophisticated regional transportation modeling:
• Level 1 Trending Forecast or similar forecasting methodology should be used in areas where there has been slow or steady growth or where there is not enough data available to perform a cumulative analysis.
• Level 2 Cumulative Analysis or a similar forecasting methodology is preferred over the Level 1 Trend Forecast analysis in areas that are growing quickly, where differing rates of growth exist, and when adequate data is available.
  
• For jurisdictions with a population greater than 15,000 or where a transportation demand model exists (regardless of size), a Level 3 Transportation Model or similar forecasting methodology is preferable.
• Metropolitan areas (50,000+ persons) require a Level 4 Regional Transportation Model or similar forecasting methodology.
  

Note: Forecasting future travel demand within metropolitan areas may be an iterative process given the requirement for local agencies to not increase vehicle miles traveled (VMT) per capita within the planning horizon. Local agencies will likely complete an initial forecast; then revise and review the forecast to evaluate the impacts of potential land use changes and transportation facility improvements on VMT per capita. Each iteration of the model will likely create timing impacts that could affect short timelines and small budgets. Alternatively, local agencies may exclude projects from their financially constrained plan that are subject to the enhanced review process (-0830). In which case, the agency does not need to show a reduction in VMT per capita.