The M25 or London Orbital Motorway is a major road encircling most of Greater London. The 117-mile motorway is one of the most important roads in the UK and one of the busiest. Margaret Thatcher opened the final section in 1986, making the M25 the longest ring road in Europe upon opening.
M4Simon wrote: The M27 junction 9 westbound off-slip scales at about 1500m from the Landranger mapping. Doesn't alter the fact that it's still the longest slip road.
Located in London, the capital of England, the M25 is an orbital motorway that almost completely encircles the largest city of the country. The M25 or London Orbital Motorway is a British motorway that surrounds London. It was built as part of the ringways scheme.
How the M25 got its name. The same principle explains the M25, which at its oldest point (the section crossing Surrey) follows the path of the older A25. These roads are all in the South East, which forms Zone 2 of the country's motorway system. This explains why they all contain 2 somewhere in their name.