MUTCD R9-21: Bicycles Use Shoulder Only Sign
The R9-21 sign is covered in Section 9B.16 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 Bicycles Use Shoulder Only (R9-21) sign (see Figure 9B-1) may be used to designate locations on a freeway or expressway where bicycles are allowed , but must remain on an available and usable shoulder.
- Guidance · Recommended (should)The Bicycles Use Shoulder Only sign should be limited to use on freeways and expressways.
Placement and mounting
- Guidance · Recommended (should)The Bicycles Use Shoulder Only sign should be placed adjacent to the entrance ramp or entrance to the freeway at or near the location where the full-width shoulder resumes beyond the entrance ramp taper.Page 1 058 MUTCD 11th Edition Decembe r 2023 Sect. 9B.17 to 9B.18
Where to read the rest
- Full text: MUTCD Section 9B.16: Bicycles Use Shoulder Only Sign
- 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.