SE085-10 Vehicle-activated speed limit signs will soon be operating as a safety measure on the A3 at Guildford. Signs reminding drivers of the 50mph speed limit will come on when they exceed the limit.
http://nds.coi.gov.uk//content/detail.aspx?NewsAreaId=2&ReleaseID=412955&SubjectId=2
seen at 16:02, 1 April in Independent Chief Inspector of the UK Border Agency News - national.