 They use a metric called average annual daily traffic (AADT), which is a statistical calculation of the average daily number of vehicles on a segment of roadway.In 2009, MDOT's surveys calculated that the highest volume of traffic along M-65 was 6,699 cars north of the M-55 junction; the highest commercial AADT was 310 trucks along the River Road National Scenic Byway segment north to the F-30 junction in Glennie.The lowest traffic counts were the 947 cars and 107 trucks near the northern terminus in Presque Isle County.