Presumably they have exactly the same number plate reading technology that is in use in Victoria. They can very readily differentiate between vehicles that should be there, or those that are interlopers.
Can it? In an ideal world the system would be able to have filters set easily and provide different screens showing the results.
Meanwhile back in the grand bureaucracy of committee land - the reality is sadly often the reverse to common sense.
I know the NSW system used to be mostly turned off in patrol cars because it would sound alerts constantly no matter what street/road they drove down. Hopefully it has been improved in the last four years - but last time I asked the intelligence unit that was still the same.
It detects any outstanding issues such as unpaid parking/speeding fines, bail alerts, people of interest, stolen cars, registration lapsed etc etc.
But on addresses - unless you have a ring of steel then the cars can be going by in 2 or 3 lanes every fraction of a second. There is not enough time to read an address let alone be able to know where it is exactly.
For example, Highway Patrol cover more than a small local area. I admit, if I was in a Highway Patrol car on the other side of Sydney then I would not know maybe 70% of the address locations coming up on a screen as the cars pass by. Then add in reaction time.
The only way to accurately stop people leaving is to have a checkpoint. In regional NSW and other States because they don't have the police resources provided to them - many local Councils have dumped piles of earth/sand to block all but one or two inter-state access roads. Thanks to too many 4wds - one Council was reported recently spending a few thousand to get rocks trucked in to make it harder to force through.