Detour Signing, Mapping, and Monitoring
A detour is only as good as its signs and how it is watched. Clear, continuous detour signing, a shareable map, and active monitoring keep the alternate route working once traffic is on it.
Last reviewed: June 24, 2026
Why It Matters
- Drivers follow signs, not intentions; a detour that is signed at the start but not carried through fails where the signs stop.
- Monitoring catches congestion, access problems, and missing or knocked-down signs before they become complaints or hazards.
When It Applies
- For any detour, especially longer detours through multiple turns or neighborhoods.
Planning Considerations
- Plan continuous detour guide signing through every decision point, and prepare a detour map for public notice.
- Plan how the detour will be monitored and who is responsible.
Field Considerations
- Install detour signs at every turn and confirmation point so the route is never ambiguous.
- Monitor the detour and replace missing or damaged signs promptly.
Inspection Considerations
- Inspectors confirm the detour is signed continuously and that signs are present, correct, and visible.
Common Compliance Failures
- Detour signing that stops partway, leaving drivers to guess.
- Missing or knocked-down detour signs that go unreplaced.
Upstream Prevention
- Plan signing at every decision point and assign monitoring responsibility.
- Include detour signs in the inspection and maintenance routine.
Related Pages
Relevant Signs on MUTCDSignChart.com
For individual sign codes, meanings, and specifications, see the sister site MUTCDSignChart.com. The signs below link directly to their reference pages:
Official Sources
Frequently Asked Questions
How is a detour signed?
A detour is signed continuously so drivers are guided at every turn from the closure back to the original road, not just at the closure. The specific signs follow the standard and the approved plan.
Why is a detour monitored during the work?
Conditions change — signs get knocked down, traffic backs up, or the detour streets have their own issues — so monitoring keeps the detour working as approved and lets problems be corrected quickly.