[blincoln]

Maybe where you live. In the Seattle area[1], speed bumps are frequently installed on residential streets where the actual limit is 25-30 miles per hour (40-50 kilometers/hour using non-legacy units).

It's typically done in "problems areas" where a small number of people drive 25-50% or more over the limit, but it's extremely frustrating, because it forces drivers to drive way below the actual limit when crossing the speed bumps - especially if they're the bolt-down kind. i.e. the effect is to cause irritation for ~99% of drivers in order to punish a tiny minority.

[1] I'm sure it happens elsewhere in the US, too.

[Xylakant]

So if this kind would be installed, then they'd be soft at regulated speed and only solid at speeds significantly exceeding those. I doubt you'd be able to sue the city for breaking your car then - you have been warned. Still, no tear shed.