Issue for 1940 has also a distinctive cover title: Proceedings of the twenty-fifth anniversary highway conference, 1915-1940.

Conferences sponsored by the University of Michigan (1915-1943 by its College of Engineering) and the Michigan state Highway Department (with the County Road Association of Michigan, formerly the Michigan Association of Road Commissioners and Engineers, 1923- ).

Issues for 1923- include minutes of the Annual business meeting of the County Road Association of Michigan (title varies).

Proceedings of 1919 conference not published; conference not held in 1945.

Issued 1915-1926 as University bulletin, new ser.; 1927- as University of Michigan Official publication.

Indexes cumulative from 1915 included in issues for 1928-32, 1940.