Road signs ยท Work zone

Detour Sign: Meaning and What to Do

The orange rectangle reading DETOUR with a large arrow directs you off the closed road and onto the temporary route around it. The arrow points the way to go at that point; a series of the same signs, sometimes with the route number, guides you along the detour and back to the original road.

Detour Sign (M4-9), official design
The sign

Detour Sign

  • MUTCD M4-9
  • Horizontal rectangle
  • Orange with black legend and a black arrow
  • Work zone sign

A detour is not optional where the road ahead is closed. Drivers who ignore the arrow to save time reach the closure and must turn around, often in a space not designed for it, in front of the work crew the closure protects.

What to do

What to do when you see the detour sign

Follow the arrow, then watch for the next Detour sign at each decision point until you rejoin your route. Slow down; detour routes often use narrower streets and unfamiliar turns. If you lose the trail, retrace to the last sign rather than guessing through side streets.

The signs it is confused with

Tests pair it with the orange Detour Ahead diamond, which warns that a detour is coming, and with the small orange DETOUR plaque mounted above a route marker on the temporary route. The large arrow sign is the one that tells you where to turn.

Try it

Signs are one topic of ten on every test

Every state practice test covers signs, signals, and markings among its ten topics, with every answer explained. Pick your state and see how its exam asks about signs like this one; it is free, with no sign-up.

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Questions

Questions about the detour sign

What does the detour sign mean?

The road ahead is closed. Turn in the direction of the arrow and follow the detour signs until you rejoin your route.

Do I have to follow a detour?

If the road is closed, yes. Ignoring the arrow leads to the closure, where you will have to turn around in a work area.

How do I know where the detour ends?

The signs continue at every turn until an End Detour sign or until you are back on your original route and its normal signing.

What is the difference from detour ahead?

Detour Ahead is a diamond warning that a detour is coming. The Detour arrow sign marks the actual turn.

How does this sign appear on the written test?

As an orange-sign recognition question, usually alongside the diamond warnings of the same work zone.