I suspect this varies, not merely State to State, but potentially municipality to municipality within a State. The speed cameras around S2 are owned and operated by the government.
Even government police may have such incentive. So much so there's even a nickname for it: "cash-register justice".
I'm not up for a squabble here, but they're not known as "the suggestions of physics".
They're called "the laws of physics", and I gather it's as accurate as we can measure it.
If speed-trap radar is inaccurate, I suspect that's due to hardware deficiency, whether poor design,
incompetent calibration, or other operator error.