I think that that is exactly the reason why this will not get used. Many speedbumps are actually designed in a way that they are imperceptible when you go sufficiently fast (80km/h is usual)

Sounds like expert-level trolling ;)

These are speed-bumps near my mother's house in Wales: https://goo.gl/maps/hdThhzduxpp – they're sort of trapezoid, they work to slow traffic, but above a certain speed you definitely feel less of a bump too.

Your typical E-series based ambulance will laugh at speed bumps at pretty much any speed. Whether you want to be not wearing a seatbelt when that happens is a different story.

They are rarely placed where the prudent maximum speed is much above the posted speed.

I guess if there is a patient in fragile condition in the back of an ambulance that would be an issue.

Come to my city. Many limits are based on non-safety things like road noise and antiquated notions re saving fuel.

Speed bumps are common in places like huge parking lots where reasonbable varies wildly throughout the day.

Bumps are also used to bring traffic down well below the posted limits.

Most American speed limits are well above a safe speed for neighborhoods with pedestrians and cyclists. http://www.sciencedirect.com/science/article/pii/S0386111214...