Requires drivers to turn left at the intersection, prohibiting any other movement from that lane or approach.
MUTCD-style sign reference illustration. Always verify against the official CA MUTCD and Caltrans sign charts.
| Sign code | R3-5b |
|---|---|
| Federal code | R3-5b |
| Name | Left Turn Only |
| Category | Regulatory Signs |
| Shape | Rectangle (Vertical) |
| Color | White background, black legend and arrow |
| California status | Used in California per CA MUTCD |
| Typical CA minimum size | Per CA MUTCD minimum for the roadway type |
Download this sign or open the official MUTCD reference.
Official source: FHWA Standard Highway Signs, 2024 (11th Edition) — Regulatory signs.
Source: FHWA Standard Highway Signs — Public Domain. California: CA MUTCD 2026 (effective Jan 18, 2026).
Files linked from FHWA are official government publications in the public domain. CA MUTCD and Caltrans links open official government websites. Always verify against the current edition.
Requires drivers to turn left at the intersection, prohibiting any other movement from that lane or approach.
Requires drivers to turn left at the intersection, prohibiting any other movement from that lane or approach. In the field, R3-5b Left Turn Only is typically positioned at the advance warning area, ahead of the work. Common deployments include channeling traffic to a left turn at closures; lane-use control at construction-zone approaches; restricting movements when through travel is not available. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.
Used in California work zones where straight-through or right-turn movements must be prohibited from an approach, channeling all traffic to a left turn.
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: Per CA MUTCD minimum for the roadway type.
Sizes are CA MUTCD minimums and vary by roadway classification and speed. Verify against the CA MUTCD 2026 (CA MUTCD Part 2B (Regulatory Signs)), Caltrans sign specifications, and the reviewing agency.
Where it sits: Advance warning area, ahead of the work.
CA MUTCD reference: CA MUTCD Part 2B (Regulatory Signs).
In Los Angeles, temporary regulatory changes (speed, one-way, turn or entry restrictions) generally involve LADOT review, and on state highways Caltrans District 7. Regulatory authority cannot be created by signing alone — confirm the change is authorized by the agency with jurisdiction over the roadway.
Confirm that the turn restriction is consistent with the temporary lane configuration and is properly authorized. Public Ready reviews lane-use restriction signing.
These signs are typically deployed alongside R3-5b on a California TCP.
Need to require a left turn at a work-zone approach? Public Ready can supply LEFT TURN ONLY (R3-5b) 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 R3-5b Left Turn Only, visit WorkZoneCompliance.com.
Public Ready can help with R3-5b Left Turn Only — 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.
