MUTCD W4-3: Added Lane Signs

The W4-3 sign is covered in Section 2C.46 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

• Guidance · Recommended (should)
  The Added Lane (W4-3) sign (see Figure 2C-11 ) should be installed in advance of a point where two roadways converge and merging movements are not required. When possible, the Added Lane sign should be placed such that it is visible from both roadways; if this is not possible, an Added Lane sign should be placed on the side of each roadway.
• Guidance · Recommended (should)
  When an Added Lane (W4-3) sign is installed on a major roadway, the symbol should be oriented right or left as appropriate to depict the side from which the entering roadway converges, with the straight arrow representing the major roadway and the curved arrow representing the entering roadway. The sign should be located on the side of the major roadway from which the entering roadway converges.

Placement and mounting

• Guidance · Recommended (should)
  When an Added Lane sign is to be installed on a roadway that curves before converging with another roadway that has a tangent alignment at the point of convergence, the Entering Roadway Added Lane (W4-6) sign (see Figure 2C-11 ) should be used to better portray the actual geometric conditions to road users on the curving roadway.

Where to read the rest

• Full text: MUTCD Section 2C.46: Added Lane Signs
• Minimum sign sizes by roadway type are in the size section for this chapter: Section 2C.03
• Mounting height, lateral offset and retroreflectivity for any sign: MUTCD sign placement guide

Related signs in Section 2C.46