Sect. 6F.48 to 6F.50
Standard: Each detour shall be adequately marked with standard temporary route markers and destination signs.
Option:
The Detour Arrow (M4-10) sign may be used where a detour route has been established. The DETOUR (M4-8) marker may be mounted at the top of a route marker assembly to mark a temporary route that detours from a highway, bypasses a section closed by a temporary traffic control zone, and rejoins the highway beyond the temporary traffic control zone.
Guidance:
The Detour Arrow (M4-10) sign should normally be mounted just below the ROAD CLOSED (R11-2, R11-3a, or R11-4) sign. The Detour Arrow sign should include a horizontal arrow pointed to the right or left as required.
The DETOUR (M4-9) sign should be used for unnumbered highways, for emergency situations, for periods of short durations, or where, over relatively short distances, road users are guided along the detour and back to the desired highway without route markers. A Street Name sign should be placed above, or the street name should be incorporated into, a DETOUR (M4-9) sign to indicate the name of the street being detoured.
Option:
The END DETOUR (M4-8a or M4-8b) sign may be used to indicate that the detour has ended.
Guidance:
When the END DETOUR sign is used on a numbered highway, the sign should be mounted above a marker after the end of the detour.
http://mutcd.fhwa.dot.gov/pdfs/mille...4.01/6fndi.pdf

