M-125 is maintained by the Michigan Department of Transportation (MDOT) like other state highways in Michigan. As a part of these maintenance responsibilities, the department tracks the volume of traffic that uses the roadways under its jurisdiction. These volumes are expressed using a metric called annual average daily traffic, which is a statistical calculation of the average daily number of vehicles on a segment of roadway. MDOT's surveys in 2011 showed that the highest traffic levels along M-125 were the 21,229 vehicles daily between Jones and Front streets in Monroe; the lowest counts were the 2,306 vehicles per day between Stearns and Erie roads near Erie. No section of M-125 has been listed on the National Highway System, a network of roads important to the country's economy, defense, and mobility.