HL Deb 12 November 1975 vol 365 cc1964-5WA
Lord SWANSEA

asked Her Majesty's Government:

What is the nature and function of the installations beside the East-bound carriageway of the M4 between kilometre posts 69.7 and 71.3.

Baroness BIRK

The installations comprise three different types of fog detector undergoing evaluation and reliability tests; and a device (known as ORBIS) for photographing vehicles in fog and recording their speed. These instruments have been installed under a programme of research into the problems of road traffic in fog.