the problem is the driver's life outside of the car being part of the equation. Imagine a headline like AI learns the driving patterns of anime fans. How is the traffic camera gonna know which cars are being driven by anime fans in the first place? Of course drug dealers are gonna be much less likely to have drug dealer bumper stickers that might tip the cameras off.
Arrest a few hundred drug traffickers over the course of several years using non-AI techniques, then feed their plate numbers and the past decade of traffic data to the AI.