That isn't, "high speed rail", it's just well maintained rail as it's existed for over a hundred years.
Until EACH of the next 60 earthquakes requires the ultra-close-aligned strings of high-speed spaghetti (er, railroad tracks) get twisted and the tunnels damaged.
But we soooooooooooo desperately need the CO2 to be limited by speeding (empty) trains filled with empty seats between SFran and LA! (Instead of by the (less expensive) and faster and more flexible airplanes.)
It'll settle down? It won't even make it to high-speed to begin with. Problem is, it's sharing track with Caltrain and other rail companies, with the inherent slowdown and shuffling for several different entities sharing right-of-way. It's a big problem on the SF Peninsula, and "authorities" are perplexed about it. The "high-speed" trains will slow to a crawl going through the SF peninsula corridor.
We had similar promises of high-speed BART trains when the BART project was sold to taxpayers. It has never met the promises of fast transit, because trains are going much slower than envisioned or promised.
The "high speed rail" project should be abandoned in order to save taxpayers from further debt.