English: Map of the "National Network for Conventional Combination Trucks, 2009". Carried the following caption in the original:

Notes: This map should be be interpreted as the official National Network and should not be use for truck size and weight enforcement purposes. The National Network and the National Highway System (NHS) are approximately 200,000 miles in length, but the National Network includes 65,000 miles of highways beyond the NHS, and the NHS encompasses about 50,000 miles of highways that are not on the National Network. "Other NHS" refers to NHS mileage that is not included on the National Network. Conventional combination trucks are tractors with one semitrailer up to 48 feet in length or one 28-foot semitrailer and one 28-foot trailer. Conventional combination trucks can be up to 102 inches wide.
Source: U.S. Department of Transportation, Federal Highway Administration, Office of Freight Management and Operations, Freight Analysis Framework, version 2.2, 2009