Cause and Effect

My main Blip is the 'Effect' - Westbound traffic on the M62 this afternoon. 
I don't know how far the tailback stretched - but it looked a long, long way.
Just what you don't need on a Friday afternoon.
My extra is the 'Cause' - and accident on the Eastbound carriageway.
Both Blips taken from the same bridge (Round Ings Road just West of Junction 23).