From FHWA, a template

Recognizing the need for more attention to freight in the planning process, FHWA has developed a Statewide Freight Plan Template to help states include freight in their planning: “Today, one of the biggest challenges facing public sector transportation professionals is incorporating freight perspectives into the transportation planning process. The template is intended to assist State DOTs in including freight analysis in the update of their plans and/or developing a separate freight plan. The template presents options for including freight in the planning process. Freight planning should not be conducted as an isolated element, but should be incorporated into the overall planning process. To incorporate freight planning elements into the plan, several issues will be faced, including data collection, inclusion of private sector freight representatives, conflicting planning timelines and forecasting freight traffic.”
For sources of data, the FHWA suggests “There are many sources of information on interstate freight characteristics. Most are mode-specific, but some provide data on total freight movement between states and regions. Virtually all sources have limited usefulness for freight transportation planning, stemming from sampling and confidentiality constraints. The most comprehensive source of information on interstate freight movement is the national Commodity Flow Survey (CFS), conducted jointly by the U.S. Department of Transportation (Bureau of Transportation Statistics) and the U.S. Bureau of the Census. A good resource to help with the development of this section is the Quick Response Freight Manual Second Edition (QRFM).”