M-14 is maintained by 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 2010 showed that the highest traffic levels along M-14 were the 86,500 vehicles daily east of the Sheldon Road interchange in Plymouth Township; the lowest counts were the 26,641 vehicles per day west of the Miller Road interchange. All of M-14 has been listed on the National Highway System, a network of roads important to the country's economy, defense, and mobility.