Horrifying pile up on the motorway

[Sundae]

Black fog is not a known weather condition in this country.
It might have been in coal-burning times, but I doubt it's officially recognised by meteorologists now. That was a response by a member of the public.

The trouble with pile-ups is less about how far you are from the vehicle in front (although the further the better) than how close the vehicle behind is. You can still be able to stop in time and have someone behind unable to stop, plough into you and push you into the vehicle ahead.

Police suggest it was wet surface conditions, moving fog banks and (unlikely but possibly) a fireworks display taking place at a nearby rugby club which might have diverted drivers' attentions for the time it took to notice the problem ahead.

(Copyright for photo shown on picture - mods remove if I'm breaking any rules)