Q: When was the 70 mph motorway speed limit introduced in Britain?
A: The 70 mph National Speed Limit was introduced as a temporary measure in December 1965. It is often blamed on Barbara Castle, but at the time the Minister of Transport was Tom Fraser.
The reason given was a spate of serious accidents in foggy conditions, but it is often claimed that the MoT had been alarmed by AC Cars testing their latest Cobra on the M1 at speeds up to 180 mph.
It was confirmed as a permanent limit in 1967, by which time Barbara Castle (a non-driver) had become Minister of Transport.There was surprisingly little debate at the time: the fact that the average family car of the time could only just exceed 70 mph perhaps had something to do with this.
It should be noted that this limit applied to all previously "derestricted" roads, not only motorways.
From http://www.speedlimit.org.uk/faq.html
eddie
Good historical information there Eddie

Must not forget the fuel crisis in the early seventies that led to:
[size=24]"[/size]1974: New speed limit to curb fuel use
British drivers must adhere to reduced speed limits from midnight tonight as the government tries to save fuel.
Speed limits on motorways will remain 70mph (112kph), but on dual carriageways they will become 60mph (96kph), and on all other roads 50mph (80kph).
Motorists could previously drive up to a limit of 70mph.
Anyone breaking the new restrictions will be reported, though not necessarily summoned.
The maximum penalty for speeding has been doubled to £100.
[size=24] "[/size]http://news.bbc.co.uk/onthisday/hi/dates/stories/december/15/newsid_2559000/2559807.stmThese limits were a little frustrating at the time, but the queues we had to join to get a limited amount of fuel were horrendous! I was driving a company Escort Mk1 on business across the south east, and I struggled to fill up the tank, so on motorways I certainly kept my speed / fuel consumption down!
