MUTCD R4-9a: STAY IN LANE Signs
The R4-9a sign is covered in Section 6G.07 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)A STAY IN LANE (R4-9) sign (see Figure 6G-1) may be used where a multi-lane shift has been incorporated as part of the TTC on a highway to direct road users around road work that occupies part of the roadway on a multi-lane highway.
- Guidance · Recommended (should)A STAY IN LANE TO MERGE POINT (R4-9a) sign (see Figure 6G-1 ) should be used during late merge operations (see Section 6N.19) to direct traffic to use all available lanes until the merge point is reached.
Where to read the rest
- Full text: MUTCD Section 6G.07: STAY IN LANE Signs
- Mounting height, lateral offset and retroreflectivity for any sign: MUTCD sign placement guide
Related signs in Section 6G.07
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.