relevant xkcd:

https://bestmotherfucking.website/

The section control technology youre refering to is already being used in some countries, and they ofcourse automatically send you your speeding tickets. 3-5 mph would only be a marginal fine tho, if there even would be a fine at all. I dont understand though how that would be any different from normal speed checks, except for the fact that it might be more accurate.