1970s speed limit ?

zardoz

zardoz

New Member
I was just a nipper when the first oil crisis happened in the 1970s, but i do recal a big fuss that was made over a cut in the national speed limits on motorways. Did it used to be 80mph which was cut to 70?. I am sure it did but nobody i ask seems to be able to remember a time when the limit was higher that 70mph (even though in the early days of UK multi-lane driving we had no speed limit on the first motorways, when they were opened in the 1960s)
 
zardoz said:
I was just a nipper when the first oil crisis happened in the 1970s, but i do recal a big fuss that was made over a cut in the national speed limits on motorways. Did it used to be 80mph which was cut to 70?. I am sure it did but nobody i ask seems to be able to remember a time when the limit was higher that 70mph (even though in the early days of UK multi-lane driving we had no speed limit on the first motorways, when they were opened in the 1960s)
Click to expand...

IIRC the current 50 60 70 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 Ministry of Transport 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.



In December 1974 the speed limits were reduced on dual carriageways and other roads (not motorways) to save fuel during the fuel crisis.
 
The limit was set at 56mph as this equated to 2600rpm which was meant to be the most economical speed for engines to operate at.

For the scientists out there, if a modern car doesn't get into top gear until 70mph and is only doing 80 - 90 at 2600rpm what would the most economical speed be today ?
 
Hi John

That's the speed limiter setting for buses etc, rather than the speed limit on the road.

I remember completely derestricted roads, and yes, my father took our new '65 2000 up to the bit of the M1 that was open in order to score his first 100mph! I also remember the first fuel crisis and the first temporary fuel saving speed limit - I have the idea it was 50 on ordinary roads and 60 on dual carriagways and motorways? It didn't seem too onerous at the time - cars have got much faster since!

As to most economical cruising speed, well your playing off overall gear ratio, engine efficiency curve and aerodynamic efficiency so there isn't a single answer for all cars. On most of the cars I've owned recently it seems to work out (by trip computer read out) around 60. But it's a jolly good pub discussion isn't it!

Chris
 
keanej said:
The limit was set at 56mph as this equated to 2600rpm which was meant to be the most economical speed for engines to operate at.

For the scientists out there, if a modern car doesn't get into top gear until 70mph and is only doing 80 - 90 at 2600rpm what would the most economical speed be today ?
Click to expand...

I believe that 56mph was worked out as a good average of when a car has overcome the inertia but hasn't yet hit the wind resistance.

They are actually both curves as some ineretia is overcome at 5mph and there is some wind resistance also at 5mph.

Where these curves cross (inertia reducing and wind resistance increasing) is on average 56mph.

So on a normal car, aim for 56mph if you want to save petrol.
 
chrisyork said:
That's the speed limiter setting for buses etc, rather than the speed limit on the road.
Click to expand...

I hate to nit pick but buses are actually set at 100 km/h or 62mph the odd thing is that commercials are set at 90 km/h or 56 mph & yet the sticker in the cab must read 85 km/h or it will fail it's test :?

Regards Colin
 
About to throw a bit of a spanner and hopefully open a debate!

Should the speed limit be increased from 70 up to, say, 80 or 90 MPH (or even higher)?
 
Most motorways are very similar to large car parks, far too busy and full. Increasing the speed to 80 mph or more wouldn't get my vote. Modern cars insulate you from noise, feedback from the steering, they give you no real indication of just how fast you are going, in my view.

Interesting question though :)
 
Dave here showing his age! :p

Seriously though, if that happened today, I am sure the queues would case a (very) long tailback!

Anyone remember the 2000 petrol shortage? That was pandemonium! :-S A family friend had their tank drilled and petrol stolen one night!
 
In Australia, the open road speed limit depends both on the road and the state in which you are in. The open road limit is usually 100kph while on some divided roads (certainly in New South Wales) it is 110kph.

The Northern Territory until only recently had no open road limit, so driving at 300kph was quite legal. A limit has now been introduced of 130kph.

Distances between the state capitals are huge so I don't imagine that there will ever be a reduction in open road limits in Australia. As an example, from Sydney to Brisbane or Melbourne in round figures 1000km. To Adelaide from Sydney,.1500km, Sydney to Darwin 4200km, Sydney to Perth 4200km.

Ron.
 
Should the speed limit be increased from 70 up to, say, 80 or 90 MPH (or even higher)?
Click to expand...

Most people appear to be doing 80+ anyway these days, so not much need to increase the limit. As far as I can tell most british drivers only use the speed limit to govern the speed they drive past cameras, the rest of the time they drive at whatever speed they feel like. :roll:
 
I seem to remember an advisory expert report recommending the speed limit be increased to 85 mph on motorways which would be more efficient and also safer as it was thought more people would then stick below 85 mph than was the case at the time with the 70mph limit. I think this was not long before the Blair government won its first election. Nothing then happened.

At the time there was also talk of possible measures to restrict the number of cycles on the roads which were seen by many as dangerous. I cannot remember whether it was tests for cyclists (children must pass cyclists proficiency test for example) or compulsory insurance. I took the cycle proficiency test at school many years ago. We were encouraged to do this by the school who did not allow pupils to cycle to and from school without it. That is the fifties for you! How things have changed! My son has insurance for his bicycle which covers third party damage but I doubt if many other cyclists bother or indeed care!

Cheers Tony Bunting
 
ajcb said:
At the time there was also talk of possible measures to restrict the number of cycles on the roads which were seen by many as dangerous.
Click to expand...

Interestingly there was a report on the news this morning that suggested the only way to make roads safer for cyclists was for more people to cycle :?
 
You can get a report with whatever recommendation you like these days. It means nothing .All you have to do is find someone who's principles are for sale to the highest bidder
 
You must log in or register to reply here.
Back
Top