It was on this day in 1986 that the final section of London’s 117 orbital motorway - the M25 - was officially opened to traffic.
The opening ceremony took place in the section between J22 (London Colney) and J32 (South Mimms) with the ribbon-cutting performed by Prime Minister Margaret Thatcher who proudly proclaimed the road as a “great engineering achievement.”
The idea of an orbital motorway was first mooted as early as 1937 in a Highway Development Survey but little was done to progress such plans until the late 1960’s, with construction not actually beginning until 1973.
In all the motorway - the second longest orbital road in Europe behind the Berlin Ring - cost over £1 billion and used well over two million tonnes of concrete.
Originally built almost wholly as a dual three-lane motorway, much of the road has had to be widened to help alleviate ever-increasing congestion (well over 200,000 vehicles use the road daily) which has seen it widely-maligned the “world’s biggest car park.”