List of Michigan County-Designated Highways

List Of Michigan County-Designated Highways

The County-Designated Highways in Michigan comprise a system of primary county roads across the state. Unlike the Michigan State Trunkline Highway System, there is a zone arrangement to the numbering of these highways. The CDH system was created in 1970 in response to the business concerns of a woman from Saugatuck. Her one-woman crusade in the 1960s started after the highway in front of her motel was turned over to local control as a county road and removed from state highway maps when the nearby freeway opened. After nearly a decade of efforts, the two test highways were designated, one each in the Lower and Upper peninsulas of the state and included on the 1970 state highway map. The CDH system was created and expanded in scope c. October 5, 1970, after it was approved by the County Road Association of Michigan and the State Highway Commission.

The system uses eight lettered zones which are divided by major state highways. Each county road in the system is designated with the zone letter followed by a number. Six of the zones, A–F, are in the Lower Peninsula while the Upper Peninsula is divided into the remaining two, G and H. There have been a total of 71 different highways designated in seven of the zones; as of 2010 no E highways have been named. Participation by the county road commissions is optional, and not all counties use the system. One additional highway, H-16, has appeared on state maps since the 1980s although it is not a part of the system.