I do like these (most of the time).
The speed signs let me check when my radar detector goes off and then how close I get to the sign before it can detect my motorcycle and post the speed. It gives me an idea of how my bike will perform with police radar. My radar detector goes off at the same distance, car or bike, but on the bike I can get twice as close to the sign before the radar return signal is strong enough for the sign's radar to read. Well, except for the car I have now, it has almost the same stealth factor as the bike. My car is low and has a very rounded front profile. Unfortunately, the sign quite readily and willingly will post the speed of the car/truck way behind me until I get close.
There is always a but... The local town of Plaistow NH hides a cruiser with a radar gun out of sight from the road but where they can read the speed sign. A
unlucky SOB wildly dangerous miscreant drives past the sign at some important amount over the posted speed limit and the sign posts his speed; the cop reads the sign and then shoots you with his radar gun for a positive kill. Your radar detector can't help you like this, even with arrows on the detector.
An unrealistic speed threshold like 1 mph doesn't change a thing. Any LEO that has a reason to want to stop you can pull you over anyway at 1 mph, or pull you over because your tire touched the yellow line or any other marginal violation. There are some states where the courts will charge you for contesting a ticket, under the pretense of paying the court costs. In this case the 1 mph could be misused. Massachusetts:
I got a traffic ticket and want to challenge it. What do I do? If the “criminal complaint application” or “arrest” box is checked, then you have been charged with a crime. Your case will go before a judge or magistrate as a criminal matter. If you are also charged with civil infractions, they will be covered during the criminal hearing. You cannot challenge them separately.
Send the citation and a $25 filing fee to the Registry of Motor Vehicles (RMV) at the address listed on the back of the citation. Mail the citation within 20 days of the date you were cited. Pay the fee by check or money order.