So this is an idea I haven’t heard before. It’s been a common lament that lawsuits under policies like NEPA and CEQA drive up the costs of construction projects. Most of those projects are roads, and the laws were famously passed in response to the damage to communities caused by the freeway expansions of the Eisenhower era.
Railroads tend to have tight grade and curvature requirements, making them hard to change in response to complaints. They also take up much less space overall and are usually more energy-efficient. Even though most infrastructure impacts are from roads, I’m confident the average rail mile is more likely to be subject to litigation than the average road mile.
The effect is perverse, because railroads typically serve more people in the same amount of space. Reducing the cost in money and time of building LRT could change the trajectory of many growing cities. Since most (non-rail) projects won’t be affected, we can count this as a compromise.
A NEPA carve-out for rail projects, and corresponding state legislation, together with some standard requirements for pedestrian crossings etc, could go a long way in making rail projects affordable for American city governments.
As a side note, according to Wikipedia, about 117 million people — a third of Americans — live in one of the CSAs attached to NYC, LA, Chicago, DC, SF, Boston, Dallas, Philadelphia, Houston, Atlanta or Miami. All have rail systems, and with populations near or above 7M, could certainly support a good one, even though a lot of that population is very peripheral, but the point of the CSA designation is that the areas are economically connected, so it probably matters.