MUTCD M4-2P: BY-PASS Auxiliary Plaque
The M4-2P sign is covered in Section 2D.18 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 BY-PASS (M4-2P) auxiliary plaque (see Figure 2D-5 ) may be used to designate a route that branches from the numbered route through a city, bypasses a part of the city or congested area, and rejoins the numbered route beyond the city.
- Standard · Required (shall)If used, the BY-PASS auxiliary plaque shall be mounted directly above a route sign.
Where to read the rest
- Full text: MUTCD Section 2D.18: BY-PASS Auxiliary Plaque
- Minimum sign sizes by roadway type are in the size section for this chapter: Section 2D.05
- 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.