The M602 is one of those rare things: a motorway designed to get traffic straight into a city centre. That's a very literal description, too, because a surprising proportion of the M602 is built in a perfectly straight line, running directly alongside the Manchester to Liverpool railway, the world's first inter-city line built in the early 1800s.
It was - like all urban motorways, it often seems - meant to go further than it does today. It terminates in Salford, transferring most of its traffic onto the A57 Regent Road towards Manchester city centre. The proposed extension of the M602, that would have carried it east to connect directly to the A57(M) Mancunian Way, never materialised.
Nonetheless, the M602 does its job very well. It's mostly sunken into a deep trench, minimising its impact on its neighbours, a range of residential areas and Eccles town centre. It links to the M60 and M62 at its western end, giving easy access both to Manchester's outer ring road and to onward motorway connections towards Preston, Liverpool and (for the brave) places outside Lancashire.
At its western terminus, the M602 flows directly into the M62 towards Liverpool. The two of them look for all the world like one motorway passing straight through, in an obvious east-west line from central Liverpool to central Manchester. There's a reason for that. The original plan was for one motorway between the two cities, to be called M52. It didn't happen because, while the earliest parts of the motorway were under construction, the idea of a coast-to-coast motorway called the M62 gained favour, and the western part of M52 was borrowed to create the section of M62 from Liverpool to the outskirts of Manchester. That left a stub of motorway towards Manchester city centre that didn't seem quite right for the M52 number, and so the M602 that we know and occasionally love was born.