They use them against the SeattLunatics on I-5 in Washington. I’ve seen them go from a steady 60mph to 50mph - and then moments later downshift again to 40mph. Even if you were lucky to have noticed the first change you likely didn’t see the second.
“Ignorance is no excuse of the law” - JBT
“They use them against the SeattLunatics on I-5 in Washington.”
Funny - I’m not sure I ever viewed those things as a speed limit sign - more just as a warning of what the traffic was like up ahead. I suppose now I should pay more attention to my actual speed! (Or not - if all the traffic is moving at 60+ the worst thing one can do is be going 50.)