When the remainder of the freeway for I-75 was completed between Roscommon and West Branch in 1973, M-18 was rerouted at Roscommon to run northeasterly over the routing of M-144, a highway that had existed since 1940.
In 1973, when the final stretch of I-75 between Roscommon and West Branch was completed, M-18 was rerouted at Roscommon to follow the route of M-144, a highway that had been in use since 1940.