Caution Signals Modified Plaque

Additional Details

MUTCD Section 2C.29 Advance Traffic Control Signs (W3-1, W3-2, W3-3, W3-4)

Standard: The Advance Traffic Control symbol signs (see Figure 2C-4) include the Stop Ahead (W3-1), Yield Ahead (W3-2), and Signal Ahead (W3-3) signs. These signs shall be installed on an approach to a primary traffic control device that is not visible for a sufficient distance to permit the road user to respond to the device (see Table 2C-4). The visibility criteria for a traffic control signal shall be based on having a continuous view of at least two signal faces for the distance specified in Table 4D-1.

Support: Permanent obstructions causing the limited visibility might include roadway alignment or structures. Intermittent obstructions might include foliage or parked vehicles.

Guidance: Where intermittent obstructions occur, engineering judgment should determine the treatment to be implemented.

Option: An Advance Traffic Control sign may be used for additional emphasis of the primary traffic control device, even when the visibility distance to the device is satisfactory.
Word messages (W3-1a, W3-2a, W3-3a) may be used as alternates to the Advance Traffic Control symbol signs.
A supplemental street name plaque (see Section 2C.49) may be installed above or below an Advance Traffic Control sign.
A warning beacon may be used with an Advance Traffic Control sign.
A BE PREPARED TO STOP (W3-4) sign (see Figure 2C-4) may be used to warn of stopped traffic caused by a traffic control signal or in advance of a section of roadway that regularly experiences traffic congestion.

Standard: When a BE PREPARED TO STOP sign is used in advance of a traffic control signal, it shall be used in addition to a Signal Ahead sign.

Option: The BE PREPARED TO STOP sign may be supplemented with a warning beacon (see Section 4K.03).

Guidance: When the warning beacon is interconnected with a traffic control signal or queue detection system, the BE PREPARED TO STOP sign should be supplemented with a WHEN FLASHING plaque.

MUTCD Section 2C.43 Use of Supplemental Plaques
Option: A supplemental plaque may be displayed with a warning sign when engineering judgment indicates that road users require additional information beyond that contained in the main message of the warning sign.

Standard: Supplemental plaques shall be used only in combination with warning or regulatory signs. They shall not be mounted alone or displayed alone. If used, a supplemental plaque shall be installed on the same post(s) as the warning sign.

MUTCD Section 2C.44 Design of Supplemental Plaques
A supplemental plaque shall have the same color legend, border, and background as the warning sign with which it is displayed. Supplemental plaques shall be square or rectangular.