M1 Motorway Guide | The Backbone of Britain

The M1 Britain's first inter-urban motorway opened on 2 November 1959, running between Watford and Crick alongside two spurs, the M10 and the M45. In its early days there were no speed limits, no crash barriers and no central reservation. It took four decades and four construction phases to finish the road: most of it was built between 1959 and 1968, the southern end was extended in 1977, and the northern end only reached the A1(M) at Hook Moor in 1999.

Today it runs 193 miles through ten counties, and the numbering still carries its history — there is no Junction 3, originally earmarked for an A1 link that was never built. London Gateway services now sit roughly where it would have been. The most unusual stretch is Tinsley Viaduct near Sheffield, where the motorway takes the upper deck of a two-tier structure with the A631 running beneath it.

Most of the route between Junction 6a and Junction 35a is now smart motorway, with variable speed limits and widespread average speed cameras. And the middle is the bit drivers remember: Watford Gap to Leicester Forest East is 37 miles with no service area — the longest gap on the road.