I have found it very upsetting to witness a serious accident.
All too often excessive speed has been the major cause of an accident proving serious or even fatal.
Personally I think that speed limits should be rigorously enforced. Putting up warning signs of speed cameras and allowing sat-navs to warn drivers of speed cameras is nothing but a farce. On the several occasions I have used a taxi here, the taxis have all been driven almost constantly at 40 to 45 mph in a 30 mph area. That's an indication how ineffective the police force is here.
Driving over the speed limit here is the norm, I'm afraid.