Drivers move fast on island backstreet? (9)

I believe the answer is:

motorists

'drivers' is the definition.
(motorist is a kind of driver)

'move fast on island backstreet?' is the wordplay.
'move fast' becomes 'motor' (I've seen this before).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'island' becomes 'is' (geographical abbreviation).
'backstreet?' becomes 'ts' ('st' backwards).
'motor'+'is'+'ts'='MOTORISTS'

(Another definition for motorists that I've seen is " road-users".)

I've seen this clue in the Sydney Morning Herald.

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