Where is it?
Infesting several miles of the M1 south-west of Nottingham. You will have to scroll up and down the motorway using the map above; this Bad Junctions listing includes junctions 23A, 24 and 24A which form one nightmarish complex.
Parts of this junction have been significantly rebuilt since this page was written. The layout described here ceased operation in 2018.
It was nominated by Clive Jones.
What's wrong with it?
Unlike most Bad Junctions, this one is not content to squat in one location and quietly fester. No, it roams up and down more than three miles of the M1, meaning that you can't just get tangled up in it and then move on — instead it just goes on and on, presenting one horror after another.
The southern end isn't too bad, with free-flowing connections between the A42, A453 and M1 — on its own, in fact, junction 23A isn't bad at all. The trouble is that it's linked to two other junctions, and all three are needed to make the full set of connections between all the roads here. Junction 24 is a huge signalised roundabout bunged up with traffic, which has (or, at the time of writing, is very shortly to have) three dual carriageways plugged in and some emergency remedial work in the shape of a cut-through on the west side.
Junction 24a is the crowning glory, though: a bizarre concoction of free-flowing sliproads that somehow still tangle up half the A50 in a difficult-to-explain roundabout.
Linking all three junctions, alongside the M1, is a dual carriageway. It's part A50, part A453, and all a bit rubbish, with flat T-junctions for local traffic, farm accesses and lay-bys full of lorries.
Why is it wrong?
Like all the best worst junctions, it happened slowly and without a plan. A seed was planted back in 1965 when the M1 opened as far as junction 24. It was, back then, a roundabout for the A6 with space for a future connection to the proposed M17 Kegworth Bypass. As new roads arrived and existing roads were improved, modifications and new connections accreted in layers, like limescale in a kettle. Now it doesn't boil properly any more, and whenever you make a drink using the M1 around Nottingham, you get bits floating in your tea.
The worst part is that so much of it was well-intentioned. Junction 23A is a perfectly good design, but it doesn't work on its own and it relies on the junction 24 roundabout to function. Junction 24A is the newest component, opened around 2000, and is only really a terrible design because it's the first stage of a proposed improvement scheme that would have sorted out the whole complex. With the rest of the proposed sliproads and free-flow links, 24A — and the rest of the stuff here — would have been impressive and fit for purpose. But without that cancelled scheme it makes very little sense.
What would be better?
There are some official plans to fix this, but — oh, this goes without saying, doesn't it? — they are now quite different to the plans that existed when 24A was designed. There will be fewer free-flowing connections and 24A will continue to make almost no sense.
So what would be better than that? Three things would do most of the job: the first is to make some changes so that the dual carriageway up the west side is free-flowing, with a flyover across the roundabout at junction 23A, a flyover to bypass the roundabout at 24 and one more to get rid of the roundabout at 24A. That would reduce problems at junction 24 and enable traffic between the M1 and A50 to free-flow in both directions.
The second is to connect the new A453 dual carriageway towards Nottingham to the M1 by south-facing free-flow sliproads, so that traffic to and from that route can reach the A42 and M1 without passing through any roundabouts.
The last thing that might be necessary is to tip a sachet of anti-limescale powder into the junction and boil it three times to get rid of all that crusty build-up.
It wouldn't take too much imagination to reduce the traffic on the J24 roundabout significantly by extending the line of the A50 across to meet the A453 towards Nottingham freeflowing.