Page:UK Traffic Signs Manual - Chapter 8 - Part 1 (Traffic Safety Measures and Signs for Road). Designs 2009.pdf/111

SIGNING PRINCIPLES The initial sign, used to indicate the area in which cameras are used to enforce mandatory speed limits, is either to diagram 878 variant or diagram NP878.1. The latter sign may now be used at sites where speed limit enforcement is being carried out by means of average speed measurement. The sign to diagram NP878.1 is currently authorised for use only on motorways and trunk roads in England and its use on any other roads will require authorisation by the Overseeing Organisation.

The speed camera signs to diagram 878 variant or NP878.1 must be placed not more than 1km from the first speed camera housing in the direction being enforced.

Speed camera repeater signs to diagram 879 should be located at around 1 km intervals on alternate sides of the carriageway, downstream of the sign to diagram 878 variant or NP878.1 and should be co-located, if possible, with the speed limit repeaters on a common grey or yellow backing board as shown. The signs and the speed camera must be placed to be visible to the driver in the same view. Additional signs may be required to achieve this.

The area where police carry out checks on the speed of vehicles (either by hand-held or vehicle-mounted equipment) is indicated by signs to diagram 829.5. The initial pair of signs should be located upstream of the initial mandatory speed limit signs (generally between 50m and 100m upstream), with repeater signs at around 1 km intervals and at intermediate junctions. Care must be taken that these signs do not obscure drivers’ view of the speed limit signs. They may be displayed only if police carry out speed checks on a regular basis. 110