As David mentioned earlier this month California is already in a huge budget deficit but that didn't appear to deter voters from passing prop 1A and committing over 19 billion to the project which is expected to take a minimum of 8-11 years for an 'initial segment' to be operational. The California train will connect LA and San Francisco in about 2.5 hours and has the capacity to revolutionize local commutes. For instance, part of the line will travel between LA and Irvine, currently a 1-2 hour drive, often in traffic. The system will also connect Oakland with San Jose, helping ease traffic congestion for daily commuters, and providing them an alternative.
It's worth noting that sections of the TGV in France were met with tremendous opposition but now that the lines are completed they have become a modern day convenience allowing for commutes between Paris and the rest of France and increasing property values near the train stations. We'll have to see if California's risk will be worth it in the end.