>>1998781People here are talking about technology and are being retarded,
The more simple answer is that an expensive track plus hard to find unused land that doesn’t get snatched up by real estate speculators whose whole thing is to blow the price of property into the stratosphere, thus making any attempted infrastructure project get annihilated by the sheer price of land acquisition.
Like, half of the reason California hsr is so fucked is because they keep getting into debates with property owners who want to charge the state the value of their land based on their predictions of how the line will inflate the price.
France built much of its rail by literally seizing land for public good or underpaying it via the boot of the state. China does the same thing, and doesn’t bother to pay land owners what they want for the property.
The vast majority of existing rail in America was built privately by independently wealthy robber barons who hadn’t yet gotten ravaged by anti trust laws, and the trans continental lines were literally given that land for free provided they linked the coasts. The American state literally doesn’t have the legal infrastructure to use land at such a scale because America is a land of homesteaders and people who came explicitly for the prospect of owning land. If the state gets away with seizing land via the threat of violence on a large scale, (ignoring the many times it did that to the natives) the whole foundation of trust in American free markets will be shattered. Nobody wants to bite the bullet and do anything for the public good at the expense of the capitalists so nothing new gets built.