Where is it?
M6 junction 7, the place where the busy M6 through the West Midlands conurbation meets the busy A34, the main road from Birmingham to Walsall (and back).
What's wrong with it?
It's a perfectly nice high-capacity three-level stacked roundabout interchange, as you can see. Trouble is, some fool connected the sliproads to and from the M6 to the west to the inside of the roundabout instead of the outside. Oops! Confusing and disorienting to say the least. It also means all the traffic from the M6 joins the roundabout on the same side, and traffic from the M6 eastbound passes an entry point to go back where it just came from before it can even leave the roundabout. Plus, it looks daft.
Why is it wrong?
The most likely reason is the proximity of junction 8 — the M5 interchange — which lies about half a mile further west. The lack of room between the M5 and A34 probably meant that even shifting the west-facing sliproads at this junction further east by just a few hundred yards like this would make a big impact on weaving traffic.
What would be better?
Shifting the west-side sliproads back to the outside of the roundabout is the obvious answer, but can't be done because of how close junction 8 is. Tricky. Having all the M6 sliproads further east and looping back to the roundabout would leave the same problem of everything joining together. Maybe we'll just have to leave it!
Right to reply
It is perfect for the only move I have used it for - on two occasions. As a bypass of the M5 to M6(N) slip, which is often heavily congested, head for M6(E), and turn round at J7 - for which maneouvre you can just stay in lane from before the onslip at J8!
The most annoying part about this junction (for me anyway) is travelling northbound from Brum, on my way to the infamous J10 (I have the misfortune to live near J10).
I have a choice, I can plough on through the traffic to J10, or get off at J7 to go through Walsall (not the greatest place in the world - avoid it if you can).
My choice is decided by the matrix sign before J7, which is invariably blank. Then, when you pass J7 and go round the bend before J8, you see the queues of traffic and matrix signs flashing like it's November the 5th! Why can't the people at the control centre warn us of congestion, so we can get off at J7?
J7 of the M6 is useful if you want to avoid queues on the awful junction which is junction 8 of the M6. I just continue past the busy exit of junction 8 round to junction 7, hop off and as you can remain in the same lane to return back onto the M6 again, and return to junction 8, entering the opposite clear slip road. I usually save 5 or 10 minutes doing this in rush hour!