The M67 forms a bypass for the A57 through Denton and Hyde just east of Manchester, though not a bypass for the towns themselves, as it ploughs straight through both of them. It was intended to provide a clear route for A57 and A628 traffic to and from Sheffield. The problem is that, while building a motorway for Manchester to Sheffield traffic is a great idea, what's really needed is for the M67 to go a bit further - it would be nice, for example, if it ever got within thirty miles of Sheffield. Instead, this remains just a small part of the journey, carrying traffic through the urban area for a few miles east of the M60 but stopping long before the job is done.
The M67 forms a very good example of an urban motorway, and at the M60 end has evidence of an unbuilt flyover - locally known as the "ski ramps". At the other end, a temporary road carries the M67 to its terminal roundabout, with clear indications that the finished route was meant to pass it to the north.
Had the motorway ever been finished, it would have run from the centre of Manchester, out across the Pennines, to end on the M1 near Sheffield. In the 1970s, the plan seemed unstoppable. The main rail line between Sheffield and Manchester underwent fabulously expensive upgrades in the 1950s -electrification and the boring of a brand new Woodhead Tunnel under the Pennines - but it was run into ruin by the Department of the Environment with the intention that its tunnel could be used as an all-weather route for the motorway through the most mountainous section.
It was only when one of the best intercity lines in the country had been fully closed that a Cost On Benefit Analysis revealed that better value for money could be achieved by pouring money down a bottomless pit. The new motorway route was subsequently scrapped. Full details on the plans for the unbuilt sections can be found on the Pathetic Motorways site.
East of the hills, traces of the motorway proposals can be found if you know where to look. The A628 Stocksbridge Bypass is built on the line of the motorway, and has a remarkably smooth, sweeping alignment that would be suitable for a motorway, though it was only built as a single-carriageway A-road. It's effectively a short section of orphaned M67.
In December 2014, the government announced a multi-million pound study was to be carried out into the possibility of building a road tunnel under the Pennines to link Manchester and Sheffield, which would effectively be a modern-day completion of the project that was started when the M67 was built.