> In every example given people died, more were maimed and even more had mental breakdowns. Seems like most people aren't willing to be a part of something like that today and there doesn't seem to be any popular cause that would motivate such projects.
People are still totally willing to be part of something like that; people are as haphazard and risky as they ever were. The government won't let them because it doesn't trust people to assess the risks properly (there is evidence that the government is right; people are very bad at assessing risk).
However improving safety probably isn't going to cause the speed reductions, safety and speed don't usually conflict. The fastest way is often also a very safe way because it involves less unnecessary exposure of people to hazards. The issue is the government deciding that work flat-out can't be done (eg, can't open a mine, can't build a highway, can't build a building, can't hire/fire someone, etc, etc). There is usually a good reason but at the end of the day building infrastructure is a break-eggs-make-omelette situation. We don't know how to build infrastructure at scale without collateral damage, as it were. If we first gain consensus that something is a good idea, infrastructure will not be built.