1968 national highway functional classification study manual;
as required by Section 17 of the 1968 Federal-aid highway act.

APA Citation

United States. Bureau of Public Roads. (1969). 1968 national highway functional classification study manual: as required by Section 17 of the 1968 Federal-aid highway act. [Washington]: U.S. Dept. of Transportation, Federal Highway Administration, Bureau of Public Roads.

MLA Citation

United States. Bureau of Public Roads. 1968 National Highway Functional Classification Study Manual: As Required by Section 17 of the 1968 Federal-aid Highway Act. [Washington]: U.S. Dept. of Transportation, Federal Highway Administration, Bureau of Public Roads, 1969.