County Highways versus County Roads
- Michigan has an "intercounty" highway system in addition to locally maintained county roads. In both cases, naming conventions should follow highway naming by state.
- Numbered county highways are prefixed with A through H based on geography. Naming convention should be "CR-[Letter Prefix][#]" (i.e. "CR-D19"). In all cases, local signage should be used to designate a primary name, while the county highway designation could be an alternate name if appropriate. While these roads could conceivably be classified higher, the lowest road type used should be Minor Highway regardless of appearance or functional classification.
- A small number of counties maintain numbered county roads that are not part of the statewide A-H highway system. These roads should be named CR-[#] (i.e. "CR-388") and would typically appear as Primary Street, Street, or even Dirt Road.
State Highway Naming
The following proposal for a new national state highway naming standard is currently under review by the GLR State Managers.
- The city field for all names (primary and alternates) of limited access USA state highways (ex: M-59) should be empty and the "none" checkbox marked. This guideline only applies to those sections of state highways that are limited access and cannot have house numbers, thus making city names irrelevant.
Michigan follows the Waze Functional Clasification (FC) standard for determining what Road Type to use for all paved roads. Public unpaved roads (gravel or dirt) will always use the Road Type, even if the FC for that road segment is higher than "local". (Dirt is always dirt.)