This is an unfortunate mix of Trafford Centre "day trippers" and HGV's in/out of the Container Base and Trafford Park in general.
Not only on the motorway itself, but in the roundabouts underneath it, with complex road markings where quick decisions have to be made.
On the roundabouts I frequently see traffic in the wrong lane for where they want to go - the obvious solution is for the driver to go around the roundabout again. But what does usually happen is the driver decides instead to cut in - try to beat the traffic, the lights, etc.
Sometimes this ends in a crunch . . .