On April 1, 1980, ownership and maintenance of the portion of NY 40 that lies south of NY 142 and outside of the Troy city limits was transferred from the state of New York to Rensselaer County as part of a large highway maintenance swap between the two levels of government. The routing of NY 40 was not altered; however, the part of the route given to the county is now co-designated as CR 145 and is also co-signed as such.