http://www.legislation.gov.uk/uksi/1987/1706/section/4/made

The Traffic Signs General (Amendment) Directions 1987

Road signs

King's Printer of Acts of Parliament

2011-07-04

ROAD TRAFFIC

These Directions amend the Traffic Signs General Directions 1981. The changes are—to direction 12, to provide for the use of the traffic sign for humped zebra crossings, introduced by the Traffic Signs (Amendment) Regulations 1986 (S.I. 1986/1859);to direction 14, to correct an error in an earlier instrument (S.I. 1982/1880);to directions 34(6), 35 and 36(1)(b), to provide for black as well as grey posts for traffic signs and signals, and for black as well as grey for the backs of signs;to direction 36, to allow the use of grey or yellow faced backing boards for traffic signs; andto direction 41, to require certain traffic signs not continuously in use to display a plain grey or black face when not in use.