Each detour shall be adequately marked with standard temporary route signs and destination signs. Detour signs in TTC incident management situations may have a black legend and border on a fluorescent pink background. The DETOUR 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 signs. A Street Name sign should be placed above, or the street name should be incorporated into, a DETOUR sign to indicate the name of the street being detoured.
Federal Highway Administration Manual on Uniform Traffic Control Devices for Streets and Highways, 2003 Edition (including 2004 and 2007 revisions) (Washington, DC: United States Department of Transportation, 2007)