What am I?

Busy day today, start and finish shifted forward by 30 minutes so I made it home about an hour earlier because of better timing on the trains. As I walked through the village I met the local community speedwatch team who were out logging cars speeding on the village roads. Sadly they have caught rather a lot of people going awfully fast, including one person who had they been caught be a police constable would have lost their licence on the spot. The worst that the speedwatch can do is if you are caught three times a PC may knock on your door and ask you to not speed in future.

Today's late blip (not enough light for good DOF) is obsolete but what is it? Most people should guess easily as they were quite common, first appearing in 1977 in France and being common in most European homes until very recently.