Side Winds Likely Ahead Traffic Sign Diagram 581 RA2 Post Mountable Silver Chrome Vinyl Diagram 503 is a supplementary Option:3 4" (19mm) Buckles x100 Diagram 503 is a supplementary plate used with the “Give Way Ahead” warning sign (diagram 501) to indicate the distance to a GIVE WAY line This sign allows road users to prepare to match the speed of traffic on the main carriageway and be ready to merge Diagram 581 is an important marker for an unexpected change in driving conditions due to wind Such locations may include exposed bridges or places where vehicles emerge from cuttings in areas which are particularly prone to high winds