Going home yesterday just before five pm a moonstone job joined the M4 about three or four cars in front of me. Lost it in the traffic for a less than a minute and then found it again stopped by a downed motorcyclist in the middle lane. I don't think it was directly involved, I think it was the car in front but couldn't tell before I passed by. I imagine there was a pretty hefty traffic jam within a couple of minutes.
I didn't stop myself because there were plenty of people there, half of them on their mobiles and the motorcyclist was being helped to his feet.
V.