Comment by namibj

The problem is less from the full coverage measurements of congestion this scheme would need, and more due to the billing of almost all vehicles on almost all roads which could be used for bypassing major roads when driving congestion-relevant commutes. So main thoroughfares/arteries, pretty much anything you'd visually classify as "highway" (unless it's a dead-end), and Autobahn/Interstate.

Without cameras: How do you do the billing then? Like, what else other than ALPR or the privacy-basically-equivalent RFID tag/token stuck to the windscreen (and correlated with a camera or similar to catch vehicles with inoperable RFID tags)?

If you'd cover old-built urban cores, you could further punish the driving-in-circles tactic of avoiding multi-story parking garages that hopes to either find a surface spot during their brief empty lifetime, or even to stall until a former passenger has ran an errand and can be picked up again.