Max speed 30' Supplementary Plate - Post Mount Diagram 513.2 R2/RA2This Max Speed advisory plate diagram 513. 2 should only be used where absolutely necessary and is there to supplement the drivers own judgement. Most commonly seen when permanently installed alongside signs 512, 512. 1, 512. 2, 512. 3 or 513. The supplementary sign is perfect for warning drivers that a bend or road feature may be more severe than it appears, such as a bend that tightens as it goes on. Like most of the signage featuring wording, this