[RightFighter]

But can you tell whether they’re doing 100 or 120? I doubt it. What about a difference between 65 and 80? Pretty hard to nail down the exact speed.

[Paladin2]

Ya but, I can tell if someone is going >100mph in a 55.

Objective data is clearly better. Chase the bastard while data logging. See hardware on Volvo S60. Data logging from that is quite conclusive. The data is good enough to get b0zos on the test track nailed by the track safety officer. Trust me.