Well, that's Los Angeles. In Cascadia it's a bit different--Vancouver and Portland both have very well-functioning mass transit systems, and Seattle has an adequate but growing one which links to the Amtrak lines that go between the three major cities as well as the Empire Builder line to Chicago. I have little doubt that upgrading the Empire Builder and Cascades routes would be worthwhile.
I commute between Portland and Vancouver fairly frequently. Initially I drove because I never really considered not driving, but round trip expense wasn't really that much cheaper than flying ($120 in fuel costs compared to $175-$250 to fly) and time in airports and on planes was time I could be somewhat productive, while my ten hour round trip drive was completely wasted.
Then someone tipped me off about the train. It takes slightly longer than driving and about twice as long as flying, but it's almost all productive time. It's cheaper than flying and about the same as driving (depends what days you travel), and it's a much more pleasant experience than flying.
The only drawback is limited service (it's daily, but with limited direct service), but with better promotion and subsidies to increase demand, there's no reason service couldn't be more frequent. I'm sure there's equipment upgrades that could be made to shorten service times also.
Amtrak, in the pacific northwest at least, really is a hidden gem. It's a shame it's not more popular.
