The M60 is the Manchester Outer Ring Road, a trundling loop of more than thirty miles that forms the hub of the dense motorway network serving Lancashire.
This is a zen motorway, achieving the highest plane of spirituality, adopting the lotus position and humming serenely. Why? Because it is the UK's only circular motorway, with no start and no end. Tarmac in eternity. Not even the mighty M25 manages that.
In parts it is incredibly well-used and the section through the Irwell Valley between junctions 15 and 16, known as Death Valley by the locals, is sometimes claimed (depending on how you define "busiest") as the busiest section of motorway in the country.
The M60's problem is that it is ideally placed for everything. It is the terminating point for most of Greater Manchester's many radial motorways, so it forms a bypass for long-distance traffic. It is handy for almost all the conurbation's wealthy, car-owning outer suburbs. It is far enough out to serve as an arterial road between the city's satellite towns. As a result, every single car journey that it is possible to make in Greater Manchester is now made on the M60. (Yes, that's an exaggeration - but not by much.)
The circle of the M60 is actually a patchwork of many older roads, brought into existence in 1998 by re-numbering existing motorways around the fringes of Manchester. It consumed the whole of what used to be M63, devoured the southern sections of M66, and - most confusingly - took a bite out of the M62, which now lies in two separate parts.
The change to M60 was brought about in preparation for the final section of the motorway, which opened in 2000. The last part of Manchester's Outer Ring Road linked Oldham with Denton to the east of the city, and the opportunity was taken to create a unified circuit with one number. The legal orders for the final section refer to it as M66, so even its newest component is a stolen section of another motorway.
Its mongrel heritage means that the M60 took longer to be built than any other road: forty-six years from start to finish, or an average of 0.78 miles per year. Work started in the mid-1950s when Lancashire County Council was offered a vast amount of industrial spoil for free, and set to work piling it up by the Manchester Ship Canal, forming the approaches to a bridge on the proposed Stretford-Eccles Bypass. The Barton High Level Bridge now uses those embankments.
When the last section opened in 2000, there were no more motorways under construction elsewhere in the UK, bringing to an end a continuous chain of construction work that had been in progress since the material was laid down for the bridge approaches more than forty years previously.
The result of this bizarre heritage is that no two parts of the M60 actually feel like the same road. The former M62 across the north of Manchester feels more like a long-distance road that's really going somewhere, while the part down the western side that used to be M63 is very hemmed-in and claustrophobic. The southern side passes through Stockport town centre and is very much an urban route, while the brand new section in the east is wide, spacious and relatively quiet. The only shared attributes are the extremely frequent opportunities to join and leave. The recommended junction spacing on a motorway is about every ten to twelve miles, but the M60 has twenty-seven along the way, with the four-mile section between junctions 22 and 23 being the longest gap.