The Brazilian authorities love electronic speed traps and speed bumps, often deployed together. IMO, both of them produce results at odds with the ostensible purpose of making the roads safer. What drivers do is speed between the speed cameras or bumps and then slam on their breaks as they pass the controls.
Speed can be dangerous on the road, but more dangerous are changes in speed and that is what these things provoke. Beyond that, the speed limits in the speed traps are often significantly slower than the ordinary posted speeds. So you are cruising along at 110 kilometers per hour (about 65 MPH) and then suddenly it goes down to 80 or even 60. Brazilians I have asked about this think the real reason for the speed traps is to raise revenue. It seems that way to me too. If driver who tried hard to follow all the applicable laws could easily still fall afoul of these things just for trying to slow to the abnormally slow speed in a safe way.
Nobody can claim that the speed bumps are revenue generators, except maybe for manufacturers of breaks or shocks, but they are literally a pain in the ass … and the teeth and certainly the psyche. You cannot cross most of them going any faster than 10 MPH without suffering physical discomfort and perhaps damaging your care. And they put them in highways – yes highways. You usually get a warning sign, but it is rarely possible to slow in a reasonable way before bouncing into them. So you are rolling down the highway at the legal speed of 90 KMH, when suddenly you have to slow to 15. Officially, it is usually 40, but you really cannot do that. They fail in their ostensible purpose to calm traffic. Most drivers speed between the bumps and then break violently just as they get to them. It creates more hazard than doing nothing, IMO. The cure is worse than the illness.