MUTCD R4-1: DO NOT PASS Sign
The R4-1 sign is covered in Section 2B.36 of the Manual on Uniform Traffic Control Devices, 11th Edition. Below are the provisions from that section that describe when the sign is used and how it is placed.
What it means and when it is used
- Option · Permitted (may)The Do Not Pass (R4-1) sign (see Figure 2B-10) may be used in addition to pavement markings (see Section 3B.03) to emphasize the restriction on passing. The Do Not Pass sign may be used at the beginning of, and at intervals within, a zone through which sight distance is restricted or where other conditions make overtaking and passing inappropriate.
- Option · Permitted (may)If signing is needed on the left-hand side of the roadway for additional emphasis, NO PASSING ZONE (W14-3) signs may be used (see Section 2C.53).
Where to read the rest
- Full text: MUTCD Section 2B.36: DO NOT PASS Sign
- Minimum sign sizes by roadway type are in the size section for this chapter: Section 2B.03
- Mounting height, lateral offset and retroreflectivity for any sign: MUTCD sign placement guide
Source: Manual on Uniform Traffic Control Devices, 11th Edition (Federal Highway Administration, December 2023, public domain). Excerpts are shortened and shown out of context; read the full section before specifying a sign. Your state may still be operating under the 2009 edition or a state supplement. Official manual: mutcd.fhwa.dot.gov.