RCW 46.61.072: Special traffic control signals—Legend.

Whenever special traffic control signals exhibit a downward green arrow, a yellow X, or a red X indication, such signal indication shall have the following meaning:

(1) A steady downward green arrow means that a driver is permitted to drive in the lane over which the arrow signal is located.

(2) A steady yellow X or flashing red X means that a driver should prepare to vacate, in a safe manner, the lane over which the signal is located because a lane control change is being made, and to avoid occupying that lane when a steady red X is displayed.

(3) A flashing yellow X means that a driver is permitted to use a lane over which the signal is located for a left turn, using proper caution.

(4) A steady red X means that a driver shall not drive in the lane over which the signal is located, and that this indication shall modify accordingly the meaning of all other traffic controls present. The driver shall obey all other traffic controls and follow normal safe driving practices.