MUTCD R4-13: Slow Vehicle Turn-Out Signs

The R4-13 sign is covered in Section 2B.42 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 SLOW VEHICLES WITH XX OR MORE FOLLOWING VEHICLES MUST USE TURN-OUT (R4-12) sign (see Figure 2B-10) may be installed in advance of a turn-out area to inform drivers who are driving so slow that they have accumulated a specific number of vehicles behind them that they are required by the traffic laws of that State to use the turn-out to allow the vehicles following them to pass.
• Option · Permitted (may)
  If an R4-12 sign has been installed in advance of a turn-out area, a SLOW VEHICLES MUST USE TURN- OUT AHEAD (R4-13) sign (see Figure 2B-10) may also be installed downstream from the R4-12 sign, but upstream from the turn-out area, to remind slow drivers that they are required to use a turn-out that is a short distance ahead.

Placement and mounting

• Standard · Required (shall)
  If an R4-12 sign has been installed in advance of a turn-out area, a SLOW VEHICLES MUST TURN OUT (with arrow) (R4-14) sign (see Figure 2B-10 ) shall be installed at the entry point of the turn-out area.

Where to read the rest

• Full text: MUTCD Section 2B.42: Slow Vehicle Turn-Out Signs
• 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

Related signs in Section 2B.42