Can they get a bike with only a rear plate to identify?
Darned right they do. I've gotten tagged when my head wasn't in the game because they constantly move the cameras between various locations, and also by toll highway cameras that didn't pick up my EZPass transponder. (No toll gates, so you need to have a transponder to be on those roads.) The difference I found between them in the US and Europe is that ours won't go off till you are roughly 10+ mph over the limit. The tolerance for where the technician sets them is the "roughly" part.
Over the next decade this is all going to change. Because highway maintenance revenues are dropping so fast due to higher mpg cars and EVs, Governments all over the world are being forced to move toward collection of GPS data. They have no choice but to collect tax based on usage miles because the data is already there. The only problems are political, concerning who collects the data and who can get access. People don't realize how closely Tesla, GM Onstar, Ford SYNC, etc can monitor you and while Governments don't have the resources to continuously monitor much of anybody, they can through the companies. I've been at the Tesla factory and personally used the telemetry data for accident investigations. China's car companies are similar and I know of cases in which an electric vehicle battery was about to overheat, leading the telemetry to the great computer prompting a service person to CALL THE CAR and tell the driver to get out of the vehicle.
Having worked with NHTSA for a number of years at the end of my career, I can tell you that right now this is all in the "How are we going to do it?" stage of studies and questions about collection and privacy. The biggest issue are all the cars in operation without telemetry (basically just GPS connected to wifi or BT) and the current view is that when this happens all those owners will need to buy a EZPass-like dongle as part of renewing their registration. It is coming.
If you think that is intrusive, what's coming in the name of COVID19 protection is actual Government tracking of each of our cell phones.
In an effort to turn an unmitigated disaster into something a bit more mitigated, governments around the world are heading towards the “drastic” end of the scale to slow down the spread…
www.techdirt.com
Jared Kushner is reaching out to health technology companies about creating a national surveillance system to track the spread of the coronavirus.
nypost.com