PW-67 Chevron Curve Indicators, also known as PW67, WYC1, or a W20-2, are used to advise the direction around the corner and provide delineation on curves. Often used in conjunction with a PW curve warning / advisory speed sign combination and a PW-66 Horizontal Curve Chevron Sight Board sign. Consists of a 1 bar chevron (either left or right) design displayed on a standard permanent warning PW sign.