What's outrageous is publicly endorsing faster motorways and pretty much saying 80mph is OK when the national speed limit applies (not under speed restrictions), then quietly installing speed cameras to catch people doing over 70mph without making any announcement on your change of heart.
The problem with all speed limits is that an appalling driver that would only just pass the eyesight test and has the reaction time of a striking earthworm won't be caught (but may be killed, or kill others) doing 70mph in terrible conditions, whereas a great driver with superb judgement could be snapped doing 80mph on a well lit empty road.
The 70mph limit was imposed in December 1965 and made permanent in 1967. I think things have changed a little since then. I have no problems with speed limits on other roads, but the motorway speed limits are a joke. Motorways are built for speed - as the article says ...
"This, say critics, fails to take into account that motorways were designed with speed in mind. Opposing carriageways are separated by central reservations and crash barriers; traffic joins from slip roads — there are no junctions, roundabouts or traffic lights; the roads are free from learner drivers, cyclists and other slow-moving road users. As a result, motorways are mile for mile the safest roads."