This has probably come up before but do you think it is taught or necessary to look over your shoulder to check blindspot when changing lanes on the motorway?
I just need to add an edit. I’m specifically referring to looking over your shoulder on a motorway. Checking mirrors and blindspot is not under question
I’m still not entirely sure what you’re asking, but you are responsible for BOTH the cars in front of you AND not changing lanes with someone in your blind spot. Both accidents would be your fault if you hit someone from behind OR changed lanes while someone is already occupying it.
If there’s not enough time to look over your shoulder before you would be too close to the person in front of you, then you should slow down to maintain a safe distance from the person in front of you, THEN check your blond spot over your shoulder, THEN change lanes and re-accelerate. It sounds like this person was too close to the person in front of them and/or approaching them at too high of a speed differential to safely check their blind spot over their shoulder AND return their head to forward facing before getting too close.