As a country boy I'm completely baffled at a road being restricted during certain hours. Are you supposed to enter the area from somewhere else? Also, would they have to manually review every car from the footage? Seems like a job worse than that of a parking warden. Seems like a lot of costly infrastructure for a couple of left turns.
The heavy lifting will be done by ANPR. The local authority will have a database of registration plates of all authorised vehicles. In the context of these restrictions authorised means vehicles specifically authorised by the local authority. Its not the same as "except for access".