I wonder with NEPA if we could do “existing negative impact” studies, i.e. if this is not built, how will the environment be affected? And if the answer is “on net the status quo is worse environmentally” then permitting can proceed without further in depth reviews required for each sub-component. Like high speed electric trains should be extremely easy to pass: they remove car and plane traffic, so even if they hurt some local environments in the process of being built, the net result is better than the status quo so those micro problems are considered outweighed by the macro, unless someone can prove otherwise.
Expanding on this, private groups should be allowed to fund neutral third parties who act similarly to land surveyors: they can provide impact studies for projects the government has not planned. If the status quo is worse for the environment and more expensive to maintain, these “impact study libraries” could provide off-the-shelf projects that wouldn’t need extra regulatory approval. Advocacy groups, like say Extinction Rebellion, could reasonably fund “status quo” analyses for carbon-intensive infrastructure vs reasonable alternatives (mass transit, HSR, road diets, etc).