There are three levels of road jurisdiction in the State of Michigan: State, County and City/Village.
State roads fall under the jurisdiction of the Michigan Department of Transportation (MDOT), and include all the 'I', 'M', or 'US' routes such as I-75, M-59, M-1 (Woodward Ave.) and US-24 (Telegraph Road).
County roads fall under the jurisdiction of the Road Commission for Oakland County (RCOC), which is an independent unit of government (not part of Oakland County Government). The Road Commission has jurisdiction over all public roads in townships, except state highways, as well as many major, or 'mile-type' roads in cities and villages.
RCOC oversees the largest county road system in Michigan, with approximately 2,700 miles of roads. The Road Commission also maintains the state highways in the county on behalf of MDOT. RCOC is essentially a contractor for MDOT, providing routine day-to-day maintenance services. These maintenance activities include plowing and salting in the winter as well as pothole patching and sign and guardrail maintenance year-round.
The cities and villages maintain the final 2,700 miles of public roads in the county (townships, by law, do not have jurisdiction over roads). This includes all the local, or subdivision/neighborhood roads in the cities and villages as well as some of the major roads that are not under the jurisdiction of RCOC or MDOT.