To all the people asking why the driver didn't swerve, I can tell you why.
In your driving exam you are told if an animal is crossing the road and you can't stop, then you run over it. This isn't an exaggeration it's the
truth. Swerving on a motorway would be dangerous at that speed even if the lane either side were clear.
That is without factoring in the idea that the driver may have had a very slow reaction time.
Deer or dog, i'm undecided, but i'll do for dear.