This is kind of a big one
Way, way back me and a couple of friends were on our way back from the cinema, kind of late at night, across junction 10 of the M6. It was undergoing loads of roadworks, though at that time of night they were deserted, and the workmen had left a few odds and ends lying around, including a can of white line-marker (like spraypaint except it comes out of the bottom, rather than the side).

We immediately seized on the possibility for mischief - we saw where they had marked out the bits of the road to dig up (mostly square patches labelled numerically) and set about adding a few of our own, so 907 became 907A and we added our own area 907B before 908, which naturally became 908A so we could draw 908B and so on. Before long, we'd added fake roadworks markings all the way around the junction.

Every time I go past and see the tailbacks at J10, I like to think I'm partially responsible for the junction's terrible design, though I claim no responsibility for the abortion that is J7. That's been fucking terrible for years and ironically is the one I end up using most.
( emvee cruor deo cruoris, Tue 12 Oct 2010, 16:10, 1 reply)

I'm prepared to bet
that whoever was responsible for the design of J7 has never driven a car in their life. A piece of road design failure bettered only by the Coventry ring road.
(FirstBendBunching All four back please..., Wed 13 Oct 2010, 0:04, closed)