'Secret' traffic signs (signs illuminated only during periods of use): policy on use
|Location||National Archives (see all files stored here)|
|File base||Series MT, subseries MT 126|
For the most part this file is a series of discussions about the development of early VMS (Variable Message Sign) systems, though it largely ignores the parallel development of motorway VMS. Possibly motorway signs were the concern of another branch or division of the Ministry.
It contains discussion of VMS systems deployed in other parts of the world, including some diagrams and photographs. VMS were already used on Italian Autostrade, usually as a roller-blind system integrated with their emergency telephone and warning beacon systems. There are also poor-quality photocopied images of a French system for dispersing holiday traffic over a range of alternative routes.
Some test systems were considered by the MOT and detailed here, including rotating prisms, light-based systems, shutters of various kinds, etc.
One particular example was an investigation carried out by the London Borough of Kensington (as-was), which wanted to install an alternative route system in Shepherd's Bush using illuminated VMS. It records the difficulties they had in creating direction signs with a large surface area that appeared black when not illuminated, even with the sun shining on them, but were clearly legible when turned on. The solution appeared to be 'cold cathode' technology, whatever that was.
Contents of note
- Photographs of various foreign systems for roadside VMS and also other variable signage systems, including an Italian system popular in international airports.
- Drawings and photographs of schemes proposed in the UK.
Links to other files
- MT 112/111 Automatic emergency traffic signs: M5 Birmingham-Bristol experiment (1962-1971)
- MT 95/668 Traffic signals: emergency warning signs and signals (1962-1964)
- MT 95/669 Traffic signals: emergency warning signs and signals (1962-1964)
- MT 95/670 Traffic signals: emergency warning signs and signals (1962-1964)
People with camera copies
Chris Marshall has a partial camera copy, including all diagrams and photos.