Michael Moore thinks that GM should switch from building cars to building high-speed trains and fuel-efficient buses. We should all ride around on public transit and that'll make better use of GM's facilities.
Not in this country it won't.
Let's get real. The public transit horse left the barn about 60 years ago. Outside of a few cities, we no longer live and work in places that are amenable to public transit. We can't tear down most of our houses and workplaces, restore them to farmland, and rebuild dense 1920's style cities with trolley lines and trains. And even if we could, we don't want to.
The key to public transit is high rider density. When population densities are 10,000 per square mile or higher, then thousands of people can live within a few minutes' walk of a transit stop. This works in New York City pretty well.
After WW II, federal policies encouraged suburbanization. So did states. Housing subsidies, road construction, cheap gas, urban schools left to rot while suburban ones got money from new industry and richer neighbors, "urban renewal" that ruined some workable old neighborhoods, and tax policies that encouraged development... among other things... the country chose, foolishly, to adopt suburban development. In the meantime the population doubled and the new homes weren't in the old cities.
I looked at the population density of the United States on a ZIP code averaged basis (you can buy this data), and found under 12% -- only about 35 million people (out of over 300M) -- live in ZIP codes with a density over 7000 per square mile. In those sorts of places, mass transit lines are likely to be well-utilized. About 44% live in areas with densities between 700 and 7000. At the high end, that's amenable to some mass transit, but for the most part it's car country. And the suburbs sprawl out nowadays with larger and larger lots, with many areas having a density of a few hundred per square mile.
Workplaces are also suburbanized, of course. The huge factories of Detroit and Pittsburgh are history. We have some big downtown office buildings, of course; that's where the transit lines of Boston, New York, Philadelphia, Chicago, San Francisco, and a few other cities go. But big office and industrial parks are more likely now to spring up along major highways, especially ring roads like Washington's 495, New Jersey's 287 and Boston's 128 and 495. These are built to a lower density, not at all amenable to trains, and not very convenient for buses.
Los Angeles has some transit left, but GM bought out and closed the old lines over half a century ago. And that metro area has multiplied in population, all based on cars. It's suburbs in search of a city, a cartropolis. Phoenix, Houston, Dallas, Denver, San Jose -- big growth areas all built that way, the older core city just a tiny part of the metro area.
We also shop differently (except, of course, in a few cities like New York). We usually buy things at big stores on big parking lots, not "downtown". Cars begat malls and big-box stores; malls and big-box stores lock in the need for cars. It's way past critical mass.
So sure, GM could build trains. If it built high-speed trains, maybe the French could buy them. (Like they buy our wines and cheeses, I suppose. For the same effort, GM could build horse carriages, and sell about as many.) We can't have them here because we don't have the tracks, and we can't build the tracks because we don't have the straight rights-of-way that superfast trains require. Suburbs are in the way. In the 1950s, the construction of highways leveled thousands of homes. It would be far worse now, with more suburbanization, but that's what it would take to build new train lines to Japanese or French standards. No, it ain't gonna happen; we'll see a few lines in the western deserts, but the Northeast Corridor Acela will be track-limited. Fixing the worst of the track will do more good anyway; better to maintain 80 MPH than to jump from 20-30 much of the way to 150 on a few stretches.
Certainly the US should stop the crazy suburbanization and move towards smart growth. Certainly the fuel tax should be phased upwards to discourage waste and more long commuting. But we're far, far past the stage where a majority of our travel, or even a large share, could move back to the rails. We're stuck with the bad decisions of our parents' and granparents' generations.
Nor are all-electric cars a panacaea. They are optimized for suburban homes with carports that can take a dedicated outlet. Can you charge a car while parked on the street down the block from your city apartment? Of course not... nor at work. Hybrids are far more practical. They don't have to burn gasoline; almost anything can run a generator. A Chevy Volt at $40k will go nowhere; it'll be bling for the eco-status set.
So let's not pretend that GM can succeed building stuff that some yuppie idealists (almost always childless) think people should want, even though they don't. GM needs to build efficient, high-quality cars. And we need to move American tastes away from big cars and SUVs down to small, efficient hybrids. (Notice how many huge trucks come in hybrid, but not many small cars? The Prius is fairly large; the Civic Hybrid a luxury trim line. GM didn't come up with the Insight.) Trying to overshoot the mark, and manhattanize the rest of the country, will fail.