It's sort of pathetic how bad the US has become at public infrastructure projects over the past 40-50 years. Take a clue from cities with 1000+ years of history: you still have to keep upgrading your infrastructure, even if it means bringing in the archaeologists to sort out what you find every time.
"In 10 years" is a bit misleading, because that's just the construction time. You need to also take into account the time it took to go from "this would be a good idea" to actually starting to dig, because that's where the SF situation is currently bogged down.
http://www.crossrail.co.uk/route/crossrail-from-its-early-be... says the idea was first seriously proposed in 1974, and was then raised, dropped and batted around at various levels of politics for another 25 years before getting to "serious funded detailed feasibility study" in 2002, which didn't get the final go-ahead until 2008 (with the construction phase then being the 10 years after that and ending 2018).
One trick, shared by many rich Middle Eastern countries is Singapore's willingness to engage in labour arbitrage: they are happy to offer, say, Indians and Pakistani labourers a decent job in return for getting good infrastructure on the cheap.
It's sort of pathetic how bad the US has become at public infrastructure projects over the past 40-50 years. Take a clue from cities with 1000+ years of history: you still have to keep upgrading your infrastructure, even if it means bringing in the archaeologists to sort out what you find every time.