Interim Guidance on the Application of Travel and Land Use Forecasting in NEPA Statewide Travel Demand Modeling Committee October 14, 2010

Travel forecasts can be a source of significant disagreement. Therefore to minimize misunderstandings, additional early coordination and documentation are required to reach and archive consensus on: What was done to involve partners, stakeholders & interested parties What assumptions were made about present & future conditions What methods & approaches were chosen What procedures were carried out Goal = Defensible forecasts that are reasonable FHWA Premise

1.Scope of study need to fit project purposes and decision maker and interested party needs 2.Modeling methods, tools and data must be suitable to adequately examine alternatives 3.Early coordination, during the scoping process, is recommended to reach and document agreements on forecasting assumptions Procedural and Process Considerations

4.Project management efforts should be monitored to ensure consistency in data, results and approaches 5.The base assumptions used for the traffic forecast should be the same ones used in air quality and noise analyses 6.All forecasting efforts should be documented and archived to describe how analytical models were chosen, what assumptions were made and who made the choices. Procedural and Process Considerations -- Continued

Scope of effort Size of study area – large enough to reasonably estimate transportation and development impacts Analysis years – base years and forecast years Appropriate level of detail for forecast results– regional, microscopic, corridor PLUS reflect non-auto impacts, such as transit use Selection of modeling tools appropriate for the analysis Selection and use of data inputs – travel, land use, employment, population A. Project Conditions – Things to Think About

Review of other or previous forecasts Calibration, validation and reasonable checking of travel models The extent to which forecast results will be used to help evaluate policy considerations – TDM, pricing, managed lanes Benefits and practical difficulties associated with advanced modeling techniques Peer review Other Things to Think About

Collaborate and reach consensus early to support rest of NEPA process Involve local and regional partners and other interested parties in all parts of the forecasting process Seek agreement first on future land use scenarios for the alternatives and the methodologies to develop those estimates Document scoping and all of the interactions with other agencies during the process B.Scoping and Collaboration -- Recommendations

“If the costs of updating tools and collecting data would be exorbitant then 40 CFR, sec b may apply” “It is important to do more then simply state that the model was used to generate travel forecasts” “It is important to demonstrate that the modeling methods proposed for the study corridor have a strong foundation in observed data, are able to represent change, and credibly compare alternatives in the forecasting process”. Interesting Notes

Consider all direct and indirect effects and cumulative impacts – evaluate all alternatives in an unbiased manner In measuring effects and impacts, consider: Congestion/delay Travel choices Revenue – tolls or transit Environmental and social – noise, air quality, traffic diversion, travel benefits for different socio-economic groups, accident rates, land use redistribution Consider doing a land development impact assessment Consider region-wide growth pressure dynamics C. Forecasting in Alternatives Analysis

Change in number of trips Change in length of trips Change in mode of travel Change in route Change in time of travel Change in development patterns Change in behavior – vehicle ownership Induced Demand Components

 Explicitly define and document the no-build condition – which includes a highway and most likely transit and no-build land use forecast  Document the alternatives screening process and accompanying forecasting work, including an explanation of the screening performance measures used in the process how they affected the forecast, and how the screening process was done.  Build confidence in the forecast by identifying the principle drivers of changes in traffic volumes through an incremental buildup of forecasts for each alternative More Documentation

Clearly describe the protocol for communication between and among the project manager and forecasting practitioners In all documentation, explain what the technical data mean in relation to the decisions to be made – it is not enough to describe the technical work completed Archive forecast analyses -- preserve the ability to replicate the forecasts in the future. And Finally….