Where is it?
M60 junction 18, the notional north-east corner of a circular road, where the M62 merges in for a multiplex around the northern section, and the M66 terminates.
What's wrong with it?
This is essentially the dictionary definition of the word "shambles". Quite aside from the fact that it's another of those evil concoctions, the three-level stacked roundabout, which is laughably under-capacity for such an interchange despite having huge renovations when the M60 was created, its main fault is that the through route doesn't go through it.
Make the simple, forgivable assumption that to stay on the M60 you continue straight on, and you will end up on the M62 or M66, depending on which direction you came from. There's no way to ignore it: to stay on the M60 you either have a tight left-turn sliproad or (worse) the problem of negotiating a six-lane roundabout with traffic lights. On a motorway. Wow.
Why is it wrong?
There's a simple reason for this one. When the junction was built, it was the crossing point of two motorways, the M62 and M66. Considering the M66 finished about two miles south of here, and didn't go that much further to the north, this was just fine and dandy.
When the M60 was created as a Manchester ring road, it was mostly done out of bits and pieces of existing motorway around Manchester — it used the south end of the M66 and the M62 around the north of the city, and so it had to pass through this junction. It's been modified to have six lanes around the roundabout and signs and traffic lights everywhere, but the fact remains that it's still a roundabout!
What would be better?
How about making the M60 free-flowing? It doesn't have to be the priority route through the junction (the M62 takes most of the traffic) — just something to prevent a continuously numbered motorway from passing through three sets of traffic lights. How about tunnelling under as at M1/M62? Still bad, but better than this.
Right to reply
They should make a new interchange with the M60/M66/M62 as an interchange like the M4/M25 interchange in London.
A good layout, but there isn't the room for it at the notorious M62/M66/M60 Simister junction because you'd have to knock down all of the village of Simister plus the two schools at Clark Cross, and the houses at Oak Gate too, to fit it in.
Wouldn't it suit more to build something like a four-stack interchange here, rather than a weird roundabout one with 3 levels and too many roads?
It'd be the best option, but it still wouldn't fit. Look at Almondsbury where the M5 and M4 cross. You'd still have to knock down most of Simister village. Of course, you could always pay them to get out via compulsory purchase, but I suspect you'd need an Act of Parliament to do so. It it was a matter of clearing away commercial premises it tends to be a lot easier, although probably more costly. Of course there is tunnelling a la HS2......