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.
MUTCD-style sign reference illustration. Always verify against the official CA MUTCD and Caltrans sign charts.
| Sign code | M4-8P |
|---|---|
| Federal code | M4-8P |
| Name | Detour |
| Category | Detour Signs |
| Shape | Rectangle |
| Color | Fluorescent background, black legend |
| California status | Used in California per CA MUTCD |
| Typical CA minimum size | 24" × 12" (route marker / plaque) |
The official dimensioned layout drawings below show the exact border widths, legend and letter heights, spacing, corner radius, and the standard sizes used to fabricate M4-8P. Use them to confirm sign sizing for your road type before finalizing a traffic control plan.
| Application | Size |
|---|---|
| Route marker / plaque | 24" × 12" |
Source: CA MUTCD Part 6F & Part 2D (Guide Signs). Confirm the exact size for your road type and speed against the current CA MUTCD and the official layout drawing.
Layout drawing extracted from the FHWA Standard Highway Signs (public domain). Verify exact dimensions and sizes against the current CA MUTCD, Caltrans sign specifications, and Standard Plans for your application.
Download this sign or open the official MUTCD reference.
Official source: FHWA Standard Highway Signs, 2024 (11th Edition) — Guide signs.
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 sourcesThe 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 M4-8P 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. In the field, M4-8P Detour is typically positioned at the along the detour route at each decision point. Common deployments include used where detour conditions apply on a California project; selected and sized per the CA MUTCD and the roadway type; coordinated with the overall traffic control plan and permit. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
M4-8P Detour is used in California per the CA MUTCD. Confirm its size, retroreflective sheeting, placement, and spacing against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
Common field deployments
Agency review note
StreetsLA, LA County DPW, and Caltrans District 7 may require larger sizes or additional devices. Verify with the reviewing agency before finalizing the TCP.
Typical minimum: 24" × 12" (route marker / plaque).
Sizes are CA MUTCD minimums and vary by roadway classification and speed. Verify against the CA MUTCD 2026 (CA MUTCD Part 6, Chapter 6F, and Part 2D (Guide Signs)), Caltrans sign specifications, and the reviewing agency.
Where it sits: Along the detour route at each decision point.
CA MUTCD reference: CA MUTCD Part 6, Chapter 6F, and Part 2D (Guide Signs).
In Los Angeles, this sign must conform to CA MUTCD 2026. Work in City of LA right-of-way is reviewed by StreetsLA and the Bureau of Engineering (BOE); state highways in LA County are permitted and reviewed by Caltrans District 7; county roads are permitted by LA County DPW. Sizes, retroreflectivity, and placement must meet CA MUTCD minimums — local agencies may require larger signs based on roadway class, speed, pedestrian volume, and proximity to schools or transit.
Confirm M4-8P Detour is the correct designation, size, and placement for the condition. Public Ready can review sign selection against the TCP and agency requirements.
These signs are typically deployed alongside M4-8P on a California TCP.
Need a Detour (M4-8P) sign for a California work zone? Public Ready can help you rent or purchase project-ready signs.
Free official resource — opens official government website
Free official resource — opens official government website
Free official resource — opens official government website
Free official resource — opens official government website
Educational 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.
To understand the bigger picture around permits, agency review, lane closures, and pedestrian access for work zones using M4-8P Detour, visit WorkZoneCompliance.com.
Public Ready can help with M4-8P Detour — including sign rental or purchase, California-compliant signs and traffic control plan support, and agency-review support for Caltrans District 7, the City of Los Angeles, and LA County.
