NO LEFT OR U TURN Sign Requirements

1. When a NO LEFT OR U TURN Sign Is Used

Prohibits both a left turn and a U-turn at the location where the sign is posted, shown with the combined left-turn and U-turn arrow symbol inside a red prohibition circle and slash.

• Prohibiting left turns and U-turns together at closed median openings
• Temporary two-way or crossover operations where opposing traffic conflicts
• Intersections with shifted or realigned lanes near the work area

2. How and Where It Applies

In the field, R3-18 No Left or U Turn is typically positioned at the advance warning area, ahead of the work. Common deployments include prohibiting left turns and U-turns together at closed median openings; temporary two-way or crossover operations where opposing traffic conflicts; intersections with shifted or realigned lanes near the work area. Always confirm its size, retroreflective sheeting, spacing, and placement against the CA MUTCD 2026 and the reviewing agency before finalizing the traffic control plan.

3. Placement and Application Notes

Position R3-18 at the point where the regulation applies, per CA MUTCD Part 2B.

• Place the sign where drivers have a clear, unobstructed view on approach.
• Mount at the standard height and setback from the edge of the traveled way.
• Do not mount with other signs on the same post unless space constraints require it.

4. Standard Sizes and Visibility Considerations

Typical minimum: Per CA MUTCD minimum for the roadway type.

• Choose size based on roadway speed, sight distance, and mounting location.
• Maintain high retroreflectivity for maximum night and adverse-weather visibility.

5. California Notes

Used in California work zones where both movements must be banned at the same approach — for example at a closed median opening carrying opposing traffic, a temporary two-way operation, or a shifted intersection where either a left turn or a U-turn would conflict with construction activity.

6. Common Field or Planning Mistakes

• Temporary regulatory control not warranted or conflicts with existing control.
• Reduced speed limit posted without proper speed-setting authorization.
• Wrong-way protection (DO NOT ENTER / WRONG WAY) missing at closed approaches.
• Sign size not appropriate for the facility.