The National Highway Traffic Safety Administration are trying a new tactic to discourage speeding and calm traffic in some corridors: Fake speed bumps.
The optical illusion is described as “a flat piece of blue, white and orange plastic that is designed to look like a 3-D pyramid from afar when applied to the pavement.” There is a claim that they require little maintenance after application, but none of the tests have been run in places like Buffalo or Minneapolis, where winter is rough on roads and road markings.
I have no idea how the illusion varies from different vehicular cockpit positions, or from a bicycle of any kind.
It is also noted that as motorists realize the fake bump is there, the calming effect wears off for regular users of a route. Still, NTHSA are continuing tests, because they require no engineering and are really cheap, thus I have a feeling they really want to see data that justifies using them.