A bill to amend the definition of commercial motor vehicle in section 31101 of title 49, United States Code, to exclude certain farm vehicles, and for other purposes.

Revises the definition of "commercial motor vehicle" with respect to federal commercial motor vehicle safety laws to include a vehicle with farm-designated license plates engaged in the transportation of agricultural commodities or farm supplies, or a vehicle controlled by a farmer and used to transport such items to or from a farm, having a gross vehicle weight rating or gross vehicle weight the greater of which exceeds the minimum weight of a commercial motor vehicle as established by the state. (Current law applies to vehicles having a gross vehicle weight rating or gross vehicle weight of at least 10,001 pounds, whichever is greater.)

Prohibits the Secretary of Transportation from withholding commercial motor vehicle safety improvement grants from a state solely because it authorizes drivers of farm vehicles having a gross vehicle weight of between 10,000 and 26,001 pounds to operate without complying with federal commercial motor vehicle safety laws.