[zhyder]

To be fair, I've found cops check for traffic violations more in safe areas (e.g. Silicon Valley), than in unsafe areas (e.g. Berkeley/Oakland) where cops are busy busting real criminals. So they do prioritize to some extent.

In the Silicon Valley area, I've seen more in-town speed traps than on the freeway; I received one citation for 40 in a 25mph zone, and had other close calls. Maybe it's different where you live.

"...should be concentrating on tail gating, should be prosecuting inattentive drivers, ticketing drivers with no lane control etc etc." They probably don't do this as much as these violations are more subjective and harder to prove in court. Also there's some correlation between people who speed and people who tail-gate, etc.