Jadwin, Colonel Edgar, “Relation of the War Department to Improved Highways.” Bulletin No. 25 of the Texas Engineering Experiment Station, Agricultural and Mechanical College of Texas, May 1, 1922, p. 40.

MacDonald, “Classification and Uses of Highways,” Engineering News-Record, Vol. LXXXIII, pp. 984-985, 635.

Massachusetts Highway Commission Report, 1912.

Simonds, Frank H., “History of the World War,” Vol. I, p. 118, Vol. V, p. 115. Doubleday, Page & Company, New York.

New Jersey State Highway Commission, Committee Report on Traffic Census—Engineering News-Record, Vol. LXXXVI, p. 338.

Taylor, Colonel B., “Similarity of Military and Commercial Motor Transportation,” National Automobile Chamber of Commerce, New York.

United States Bureau of Public Roads, “A Study of the California Highway System,” Public Roads, pp. 124, 136-138, 196-197, 200-209.

United States Census Reports.

United States Department of Agriculture, Bureau of Statistics Bulletin 49. Bureau of Forestry Bulletin.

FOOTNOTES