Page:UK Traffic Signs Manual - Chapter 4 - Warning Signs. 2013.pdf/79

APPENDIX B

NOTES 78
 * 1) For the 600mm and 750 mm size triangles, the smaller x-height, where more than one is shown, is appropriate if the 85th percentile speed is 20 mph or less. Where a 50 mm x-height is marked with an asterisk, this is the standard size for 85th percentile speeds up to 30 mph.
 * 2) For the 1200 mm size triangle, the larger x-height, where more than one is shown, should be used on dual carriageway roads where the national speed limit applies or on single carriageway roads where greater emphasis is required.
 * 3) As a 1500 mm size sign is sometimes used in place of a 1200 mm sign (see note 2 of Appendix A), x-heights for supplementary plates used in these circumstances are quoted even though that particular sign may not be used on motorways or all-purpose dual carriageways with grade separated junctions. The larger x-height, where more than one is shown, should be used on dual carriageway roads where the national speed limit applies or on single carriageway roads where greater emphasis is required.
 * 4) The larger signs are intended for use on main roads when an arrow has been added to the plate indicating a humped pedestrian crossing in the minor road leading from the junction ahead.
 * 5) Although permitted by the Regulations, diagrams 530 and 530A are unlikely to be used with the supplementary plates to diagrams 572 and 573 (see section7).