[kaibee]

It could happen entirely accidentally.

"Oh, we hit for DEADBEEF at 11:00am in London, so ignore hits for DEADBEEF from anywhere else outside some Nx safety factor of the driving distance from that hit, because it has to be a false positive."

or

"Oh, we hit for DEADBEEF at 11:00am in London and again at 11:05am in London. Our cloud costs are high, so we're only going to store the most recent picture DEADBEEF, and only record the violation from 11:00am and 11:05am."

I guess these examples sound kind of contrived to me, but how long do you retain this kinda data for? 30 days? 60 days? A year?

[multjoy]

Entirely contrived. The point of the system is that you want all the hits everywhere, if your system is using any discard rules at all then it is unreliable for a prosecution.

[AnthonyMouse]

You're not thinking like a bureaucracy.

Suppose you have a system of cameras operated by the various localities. The localities are all storing the data. Then there is a central system that can query all the local systems but doesn't itself store any of the data.

The department issuing traffic citations requests an automated daily report showing every vehicle observed at multiple locations where the two sightings imply an average speed between 55MPH and 170MPH. Then the citations department takes the report and issues a citation to anyone where there is no route between those two points that allows the calculated average speed without exceeding the speed limit.

The report isn't automatically generated if the average speed was calculated to be 490MPH because cars don't go that fast so issuing a citation would trivially allow it to be challenged as a data irregularity, and the report is requested by the department issuing speeding citations rather than the one (if any) investigating data irregularities.

Now you get a ticket for doing an average speed of 87MPH along a route where the speed limit never exceeded 55MPH. You claim it's a data irregularity (cloned plate), but that's a possible speed, because the automated report didn't include the impossible speeds.

There may have also been sightings that would have implied an average speed of 490MPH, but that report was never requested so it doesn't exist. The bureaucracy comes up with some excuse for why you can't run your own reports that don't already exist. You could request the raw data and then do the calculations yourself, but then you have to make a thousand requests to each individual locality, which is purposely too much trouble for most people to bother, and even then there is no guarantee that the person who cloned your plate was spotted in a location that would have produced an impossibly high speed.

[multjoy]

><The department issuing traffic citations requests an automated daily report showing every vehicle observed at multiple locations where the two sightings imply an average speed between 55MPH and 170MPH. Then the citations department takes the report and issues a citation to anyone where there is no route between those two points that allows the calculated average speed without exceeding the speed limit.

The problem with that is that isn't how average speed cameras work, and where speeds are ludicrously high then there is a human operator looking at it.

[StackRanker3000]

So why isn’t the system already working as Gigachad suggested up the thread? Why is cloning plates feasible at all and not immediately discovered and prosecuted? Is this perhaps in the works? Or are the incentives not there?

[multjoy]

Because ANPR data isn't routinely monitored. If your car is up to date on tax and insurance it doesn't generate an alert, the presence is recorded and ignored.

People make journeys that are illogical all the time and ANPR misreads are common, so there is no justification for having a system that says "this plate has pinged simultaneously 200 miles apart", because what are you going to with that information?

When you trigger a speed camera, the police send a notice to the registered keeper. They don't search ANPR for other hits, because why would they? They're dealing with the single traffic offence in front of them.

ANPR is an intelligence tool. It is an extremely valuable one, but it isn't definitive and no prosecution would stand alone on ANPR data without other corroborative evidence.