Bluetooth and toll transponders (e.g, EZ-Pass, FastTrak) have been tracking things for decades.
First hand experience in operational rooms where both Bluetooth and the transponders are used for "traffic management" in Delaware and Washington DC. The readers are not at toll gates (only). they are sprinkled throughout highways and "high interest" areas. And, yes individual vehicles can be identified throughout their movements that is the very purpose of tracking so they can see the speed and flow of individual vehicles "to adjust intersection lights".