Speaking of safety, too many of us buy into the notions like "You can never be too safe" and "If it will save one life, it's worth it." Let's put this in perspective. There's a non-zero probability that our automobile hydraulic brake line system has a just-about-ready-to-fracture crack that could cause a serious accident that could be easily prevented by a routine daily inspection. Yet how many of us bother to inspect our car's hydraulic brake lines before we start the engine and head off to work? Doing so would be safer than simply assuming that the lines were intact. After all, NASA doesn't act so "irresponsibly." Prior to launch, they make no safety assumptions. They go through a detailed inspection of all systems, taking nothing for granted. As far as our cars are concerned, we decide that such a level of safety is not worth it.
How about the frequently heard claim "If it will save just one life, it's worth it"? As a generality, it, too, is nonsense. According to 2009 data from the Department of Transportation's National Highway Traffic Safety Administration, 33,808 people died in car crashes. I'm guessing that if Congress would mandate and enforce a 5 or 10 mph speed limit, at least 30,000 American lives would be saved.
How many people would support such a mandate? "Williams," you say, "that's a ridiculous and impractical proposal!" I'd agree but put it more truthfully, though politically incorrect. People wouldn't support such a congressional mandate because those 30,000 lives that would be saved just aren't worth all the inconvenience and costs we have to bear by having to drive at 5 or 10 mph.