So much for the first 100 years. The stories and pictures in this hefty volume are a tapestry of General Motors' first century on the automotive scene.

But what lies ahead as it begins its second century?

Oil, once cheap, now is dear; the landscape, once rural and open, now is urban and crowded. Will gridlock paralyze traffic in overcrowded cities? Will escalating demand for oil trigger chronic shortages? What will the auto industry do to adjust — indeed, to survive? The technology is promising, but the challenges seem perilous. And certainly the government will play a larger role at the beginning of this second century than it did in the first. In this final story, we'll consider some neo-Malthusian theories and GM's more optimistic expectations for the future.

The camera focuses on an intersection outside Tokyo's Shibuya railway station, through which more than 2 million commuters pass every day.

Cars creep along, bumper to bumper. Then the lights change and a huge crowd floods the intersection from every direction — a fast-moving, zigzagging human swarm so large that it obscures the pavement. A couple of marooned vehicles sit helpless amid the throng.

Then the light changes and vehicles resume their snail march. Chris Borroni-Bird turns off the video. "I don't understand how no one was killed," he remarks.

As General Motors' director of advanced technology vehicle concepts, it's Borroni-Bird's job to visualize what the world might look like a couple of decades from now.

He has studied demographic data and talked with experts in a variety of fields, but the video sums it up. Megacities like Tokyo, Mexico City, New York, Sao Paulo and Mumbai — the world's five most populous urban regions — will dominate the future. Those cities aren't known as car-friendly environments, but the population trends are clear: By 2030, about 60 percent of the world's population and 80 percent of the world's wealth will be concentrated in cities. To prosper, automakers will have to sell cars where the people — and money — are located.

In light of that, Borroni-Bird has a few predictions:

• Vehicles will shrink.

• Electric cars will claim an urban niche.

• Vehicles will communicate with each other like the cells of a very large brain.

• Self-propelled vehicles will shuttle passengers from destination to destination like computerized taxis.

How do they do it?

ENLARGE Borroni-Bird: Cars will communicate

Borroni-Bird seems most intrigued by those last two predictions. He notes the lack of jostling at the Shibuya intersection — the ability of those commuters to avoid bumping into each other.

"You have to ask yourself how people are doing this," he said. "You're able to sense somebody else's movement, then predict where they will be at any point. And then you will speed up or slow down to avoid them."

While some of this sounds like standard-issue science fiction, GM already has built a Chevy Tahoe that can drive city streets without a human at the wheel. And GM and other automakers are investing heavily in battery technology to put electric cars and hybrids on the streets.

Perhaps most important, American motorists — known for their taste for big pickups and SUVs — are moving rapidly to smaller vehicles. Nearly all the elements for Borroni-Bird's scenario are technically feasible.

Yet one can't help but wonder whether Borroni-Bird is too optimistic. The chaos of the Shibuya intersection is a common sight in today's megacities.

Global gridlock

For a more pessimistic forecast, we turn to the modern disciples of Thomas Malthus, the 18th-century English economist who predicted that rapid population growth would lead to poverty and starvation.

But the neo-Malthusians give the economist's theories an unexpected twist: A prosperous global population will generate escalating demand for cars, which will lead the world's cities to choke on their own traffic.

If the world economy and population continue to grow at the current rate, almost 3 billion cars, light trucks and commercial vehicles will clog the planet by 2035, concludes a provocative report published this year by Global Insight Inc., a consulting firm in suburban Boston.

That would be four times larger than the 2000 global fleet of about 700 million vehicles.

The resulting oil consumption, air pollution and urban gridlock would cause a breakdown of urban transit, concludes Phil Gott, who wrote the report. "Obviously this is not sustainable," Gott says. "If we continue on this path, it's the wrong path."

His logic is straightforward. Using certain economic forecasts, he assumes that every region of the world will boast an average per capita income above $5,000. In the past, whenever a region's incomes hit that point, vehicle sales typically soared. Gott assumes that trend will continue.

Gott does not actually believe that 3 billion cars will clog the world's highways. Perhaps a war, or a shortage of raw materials, or oil depletion, or a government edict, or some combination of those factors will stop that unrestrained growth, he says.

Further, he does not propose to eliminate cars. Instead, Gott predicts a future in which governments set some restrictions on vehicle ownership. He visualizes cars existing side by side with mass transit. And he foresees some interesting experiments with communal vehicle fleets.

"I might need a Prius today, an Escape tomorrow and a Durango next week," Gott says. "People wouldn't own a car. They would rent what they need. And when they go away on weekends, they might rent a Mercedes S class or a Bimmer. When we go, we want to go in style."

The oil outlook

ENLARGE Lippert: We need a "portfolio of solutions."

Now let's turn to the Malthusians in the oil patch. Fifty-two years ago, a Texas geophysicist named M. King Hubbert unveiled a theory of oil production that has entered the realm of conventional wisdom. Hubbert believed that the productivity of any oil patch — or even the entire world oil supply — followed the shape of a bell curve.

In 1956, he predicted that the United States' oil production would peak in the late 1960s or early 1970s, then start to decline. Later, he predicted that the world's oil production would peak in 1995.

Oil experts still argue about that. It isn't easy to measure the world's oil reserves, because oil producers lie about them. Saudi Arabia, for example, considers its oil reserve data to be a state secret. Are we running out of oil? And if so, what should we do?

Andreas Lippert has been thinking about that. As director of GM's Global Energy Systems Center, it's his job to figure out which fuels will be sufficiently plentiful, cheap and clean — hence, acceptable for General Motors. For the record, Lippert agrees with various oil companies that argue Hubbert was too pessimistic.

Even so, he says, it's important to move toward other fuels. Since demand for oil keeps rising, he says, we will be subject to rising prices and periodic shortages. Not a pretty picture if you rely solely on gasoline. And Lippert says no single fuel can take oil's place.

"We need to have a portfolio of solutions," he says. GM's portfolio will include ethanol, electric batteries, petroleum and fuel cells that run on hydrogen, Lippert says.

Will fuel cells ever be cheap enough for the mass market? Lippert quotes a recent study sponsored by the National Academy of Sciences, which predicts that 2 million hydrogen-powered vehicles will be on the road by 2023.

While GM is investing in those new technologies, it doesn't seem likely that the automaker or any of its rivals can single-handedly create a new supply of fuel or the infrastructure to distribute it. In past centuries, infrastructure meant things like highways and railroads — and that meant government, or at least government subsidies. But Hubbert didn't have much faith in politicians, and instead helped launch a movement called Technocracy Inc., which proposed to replace money with a unit of currency dubbed energy certificates.

Lippert isn't ready to go that far. But it's fair to ask whether the auto industry and our government have the foresight to deal with a scarcity of oil.

To visualize a healthy transportation industry in the century ahead, one must assume an unprecedented degree of cooperation between government and industry. If hydrogen is part of the answer, for example, government will have to help get it to the miracle cars that the industry creates. The details — and the form that those solutions will take — will be fascinating raw material for the historians who study GM's second century.

And what part will GM play in this work in progress?

Consider the oft-misquoted remark of former GM Chairman Charles Wilson: "For years I thought that what was good for our country was good for General Motors, and vice versa."

Fifty years ago, GM's critics took Wilson's remarks as proof of GM's arrogance. Perhaps Wilson simply meant that GM's welfare was inextricably intertwined with the nation's own.

This account of General Motors' products, ads, strikes, inventions, wars, moon buggies, Motoramas, scandals, near-bankruptcies and overseas adventures is an exciting chronicle of GM's — and the nation's — wild ride through the last century.

But perhaps the chronicle written a century from now will make it seem tame by comparison.