Guide Signs
Guide signs that mark the length of a work area, the end of road work, and the route through a detour.
Guide signs help road users navigate — they identify the limits of a work zone and direct traffic along a route. In temporary traffic control, the work-zone guide signs use a fluorescent orange background with a black legend, matching the warning signs around them.
The two core work-zone guide signs in California are G20-1 (ROAD WORK NEXT XX MILES), placed at the start of an extended work zone, and G20-2 (END ROAD WORK), placed in the termination area so drivers know normal conditions resume. The detour route markers (M-series) also function as guide signs by directing traffic along an approved alternate route.
Because guide signs frame the work zone, plan reviewers check that the stated work-zone length matches the actual limits and that END ROAD WORK is placed past the termination area. Sizes follow the CA MUTCD and the Caltrans sign specifications.
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All Guide Signs
Showing 12 of 12 signs
Informs drivers of the total length of a work zone, telling them how many miles of road work to expect ahead.
Marks the downstream end of a work zone, informing drivers that they have passed the work area and that normal conditions resume.
Identifies an approved detour route, marking the path drivers should follow around a closure when used with directional arrows.
Combines the word DETOUR with a directional arrow to point drivers toward the correct turn along the detour route.
Marks the end of a detour route, telling drivers they have returned to the original road and the detour is complete.
Directs pedestrians along an alternate accessible route when a sidewalk or crosswalk on their normal path is closed.
The G20-4 Pilot Car Follow Me sign is a California MUTCD work zone guide sign. It is shown here as an educational reference with the official FHWA Standard Highway Signs layout and California sizing guidance.
The G20-5aP Work Zone (plaque) sign is a California MUTCD work zone guide sign. It is shown here as an educational reference with the official FHWA Standard Highway Signs layout and California sizing guidance.
The M4-8a End Detour sign is a California MUTCD detour sign. It is shown here as an educational reference with the official FHWA Standard Highway Signs layout and California sizing guidance.
The M4-8P Detour sign is a California MUTCD detour sign. It is shown here as an educational reference with the official FHWA Standard Highway Signs layout and California sizing guidance.
The M4-9c Bicyclist Detour (with arrow) sign is a California MUTCD detour sign. It is shown here as an educational reference with the official FHWA Standard Highway Signs layout and California sizing guidance.
The M4-10 Detour sign is a California MUTCD detour sign. It is shown here as an educational reference with the official FHWA Standard Highway Signs layout and California sizing guidance.
Official Sources (external)
This is an educational reference. Verify sign use, size, placement, and application against the current CA MUTCD, Caltrans sign specifications, Standard Plans, and the reviewing agency. Official source links are gathered in one place.
View official sourcesEducational reference only. This is not an official Caltrans, FHWA, or local agency publication and is not legal or engineering advice. Always verify sign selection, size, placement, spacing, and application against the current CA MUTCD 2026, Caltrans sign specifications, Standard Plans, project documents, and the reviewing agency’s requirements.
Frequently Asked Questions
What is the difference between a guide sign and a warning sign?
Warning signs alert drivers to a condition ahead (diamond-shaped). Guide signs provide navigation and route information — in a work zone, that means the length of the work area and where it ends. Both use the orange work-zone background in TTC.
Where does END ROAD WORK go on a TCP?
G20-2 END ROAD WORK is placed in the termination area, past the last work activity and downstream tapers, so drivers know they have cleared the work zone and normal conditions resume.
Are detour route markers considered guide signs?
Yes. Detour markers (the M4 series) guide traffic along an approved alternate route, which is a guide function. They are also listed under Detour Signs on this site because of how they are used.
Need guide signs for a California work zone?
Public Ready can help you source work-zone guide signs and coordinate them with the rest of your traffic control plan.
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