The Michigan Department of Transportation (MDOT) maintains M-61 like all other state trunkline highways in the state. As a part of these maintenance responsibilities, the department tracks the volume of traffic along its roadways using a metric called average annual daily traffic (AADT). This is a measurement of the traffic along a segment of roadway for any average day of the year. The highest traffic level for M-61 in MDOT's 2009 surveys was 9,257 vehicles per day along the Harrison business loop. The lowest AADT was 981 vehicles daily between the Osceola–Clare county line and the Muskegon River crossing. No section of M-61 has been added to the National Highway System, a network of roads important to the country's defense, economy and mobility.