Compulsion to shift about — not that one should interrupt drivers (9)
I believe the answer is:
acathisia
'compulsion to shift' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'about not that one should interrupt drivers' is the wordplay.
'about' means one lot of letters goes inside another.
'not that' becomes 'this' (I've seen this before).
'one should' becomes 'cai' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'interrupt' means one lot of letters goes inside another.
'drivers' becomes 'aa' (I've seen this in other clues).
'this' inserted within 'cai' is 'cathisi'.
'cathisi' placed into 'aa' is 'ACATHISIA'.
Can you help me to learn more?