Specification:
Triangular road signs are available in 450mm, 600mm and 750mm sizes.
Class RA1 Engineering Grade or RA2 High Intensity Prismatic reflectivity
Wall mounted or with rear channel for post fixing
DOT Transport Diagram 544.1
In areas of street lighting (except on motorways), a speed limit of 30mph applies unless another speed limit is specifically signed.
Official specification Sign Posts.
