If a speed bump isn't clearly visible to drivers they might drive into it at speed and damage their cars or maybe themselves. I have a mildly low car (factory p

If a speed bump isn't clearly visible to drivers they might drive into it at speed and damage their cars or maybe themselves. I have a mildly low car (factory parts, just an inch lower than standard), and driving into a deep pothole at more than a crawl will bottom out the suspension. It sounds like an explosion as all the energy goes into the car's frame. If I drove into a too-tall speed bump at speed it'd probably shatter the tip of my bumper, too. The city speed bumps here have signage and highly visible paint, and a shallow enough curve that I can drive over them at the intended speed.