To the Limit:
Not so fast

The UK has had speed limits longer than it has had motor cars. The idea persists that our roads traditionally had no speed limit, and that the imposition of the National Speed Limit meant eroding an historic freedom, but in fact restrictions on the velocity of road traffic have been a feature of British law for centuries. So how did we get the limits we've got?

Do the locomotion

The first true limit may have been the 1861 Locomotive Act, which regulated the use of steam locomotives and traction engines on the open road. It set a maximum speed of 10mph in open country and 5mph in towns, with fines of £10 for speeding (a term that has to be used loosely when the limit is 5mph). Convictions must have been rare because there was no instrument either on the engine or in the hands of the police that could have indicated how fast it was travelling.

The heady days of tearing around at a breakneck 10mph were short-lived. Just four years later, the Locomotive Act 1865 lowered speed limits to just 4 and 2mph. Presumably drivers would be convicted of speeding if a policeman couldn't overtake the engine at a gentle stroll.

The 1865 Act also introduced someone who, to this day, is oddly imprinted on the popular imagination: the red flag man. A 2mph limit meant that locomotives would often reach their destination faster by parking up and waiting for continental drift to take its course, but were still considered such an unimaginable danger that a man was obliged to walk 60ft (18m) ahead of them holding a red flag. The law is referred to, even now, as the "red flag act".

There are no records to indicate how many people were mown down by engines as they stared at the strange man who was so keen to show the whole street his flag. Evidently he was at risk of becoming a spectacle in his own right, because thirteen years later the rules were changed again so that the red flag was carried just 20ft (6m) in front of the engine.

The Highways and Locomotives (Amendment) Act 1878 was a further blow to the embattled Victorian driver, demanding that engines must stop completely on sight of a horse — something that must have virtually prevented them moving at all in towns.

Light relief

When the earliest motor cars were taken out on British roads, the limits of 4 and 2mph, and the requirements to bring a red flag and park up whenever a horse peered over a fence, were still in force.

Fortunately for would-be motorists, the Locomotives on Highways Act 1896 was passed just a year after the first petrol-driven cars were built, and recognised the self-propelled car as a new form of transport. It permitted "light locomotives" to travel at 14mph anywhere they liked without additional crew or red drapery.

In 1903 the car was properly recognised by the Motor Car Act, which introduced mandatory registration and a new national speed limit of 20mph. It quickly became an anachronism, as the new technology matured and cars were able to travel safely at speed, but it persisted for 27 years. Symbols of the new motor age, like the Great West Road and the first stages of London's North Circular, were subject to this 20mph limit when they first opened.

In fact, the blanket 20 limit was to become one of the least respected laws in British history, universally ignored and widely considered irrelevant. Speed traps set up by the police to catch speeding motorists were the reason the AA was instituted, with its patrols existing to position themselves ahead of the police and warn members to slow down.

No no, no no no no, there's no limit

At face value it doesn't immediately suggest any particular meaning. But the key is in the definition of a 30mph road: one with a system of lighting. The derestriction sign was meant to show the end of an area of lighting, so it shows pure white, firmly crossed out.

Into the fog

Derestriction seemed, in 1934, to be an inalienable right of the motorist, one that Parliament was reluctant to take away. In 1965, that changed, quickly and very loudly, as stories of horrific and deadly pile-ups in the fog on Britain's brand-new motorways came one after another.

Tom Fraser, Minister of Transport, was faced with the prospect of another winter of tragic accidents and damaging headlines. His response has been discussed on Roads.org.uk before, in the shape of the "yellow peril" Motorwarn signals, and it included an experimental speed limit of 70mph on all derestricted roads.

21 December 1965 was the last day on which it was legal to drive at any speed you pleased on the open road in Great Britain; from the early hours of Wednesday 22 December all roads without a lower limit were subject to the new experimental limit of 70mph.

Opposition — from motoring groups, car manufacturers and others — was considerable, even with the fog panic that prevailed over any discussion of the motorways at that time. The Times carried an editorial warning of the risks of "the drowsy inattention which arises in the mind of the driver who, regulated by general speed limits, may fail to give his full mind to the ever-present hazards of driving at speed".

The complaints had little effect. Fraser's four-month experiment was extended further and further while its effect on accident rates was evaluated. An improvement was demonstrated, and that — perhaps combined with a reluctance to be the one who authorised motorists to drive as fast as they liked — meant that successive Ministers saw fit to keep it.

In the oil crisis of the 1970s it was lowered to a blanket 50mph nationwide in an effort to reduce fuel consumption, and was never restored to its previous state: instead we arrived at the present mix of 60 and 70mph.

We have now had a National Speed Limit for much longer than we ever had No Speed Limit, and the era of true "derestriction" lasted just 31 years. The experimental four-month limit is still, technically, a temporary measure, but it's now been with us for more than half a century.

Limits continue to be set and changed all the time — a business that requires a closer look.

* The Road Traffic Act 1930 did retain some limits — 30mph was the maximum speed for vehicles that carried more than seven passengers, and 20 was the limit for vehicles without pneumatic tyres.