Two at a time stopping vehicles and causing traffic disruption, perhaps? (6-7)
I believe the answer is:
double-parking
'time stopping vehicles and causing traffic disruption perhaps?' is the definition.
I can't judge whether this defines the answer.
'two at a' is the wordplay.
I cannot quite understand how this works, but
'at' could be 'in' (synonymous in some cases - eg at school, in school) and 'in' is found within the answer.
'a' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for double-parking that I've seen is " Where one stopped vehicle obstructs another".)