PW-1 Approaching Stop Ahead "__"m Stop Signs, also known as a PW1, WA1 or a W10-1 sign, should be installed to warn of an approaching RG-5 Priority Stop Sign, especially in higher speed areas or where the stop sign may be somewhat concealed by a hill or corner. RG-5 Priority Stop Signs are also known as RG5, RP1 or a R2-1 sign.