[jcrawfordor]

Do they directly say that they are using license plate reading? I find it far more likely that they are using the OPTICOM GPS solution which, in hybrid with OPTICOM IR, solves the same problem using cooperative radio equipment in emergency vehicles. Reporting on received IR preemption with no matching radio communication is an advertised feature of this system, whereas performing ALPR at the range and conditions of lane occupancy cameras is still largely experimental. ALPR virtually requires IR illumination, while lane occupancy cameras have no illuminators and are usually monochrome.