The rise of the "Stealth camera" and "Smart motorways"

The UK government is building over 300 miles of "smart motorways". These sections of road are subject to speed camera enforced variable speed limits - where the hard shoulder is used an additional lane at peak periods.

The cameras are grey rather than highly visible yellow - as per SPECS and GATSO cameras. The new cameras will be deployed on the M1, M4, M5, M6 and M25

There has never been a law that speed cameras must be painted yellow. DfT guidance and rules, rescinded in 2007, meant that most cameras were painted yellow with a view to claiming back the installation and running costs of the same. Since 2007, DfT guidance is that speed cameras in a lit street or highway should (not must) be painted yellow. Outside of these areas, the camera should be covered in a yellow retro-reflective sheet. Failure to follow conspicuity guidance has no bearing on enforcement of speeding offences.