It'll also give them a chance to ask the engineers and publicists the same questions they always hear: How far do they go? How much do they cost? When can I buy one?

That's what they heard Thursday during the first leg of the California Fuel Cell Partnership's three-day, 300-mile Road Rally 2005 that traveled from Sacramento to Davis to Martinez to the Golden Gate Fields horse track in Albany. Today, the rally will continue to Oakland and San Jose, and then on Saturday will conclude in San Carlos and San Francisco.

``This is a new technology. It's a different technology. We need to get people familiar with it and comfortable with it,'' said Al Weverstad, 2005 chairman of the partnership and executive director of energy and the environment at General Motors' public policy center.

At some stops, the event features speeches and static displays of the cars. At others, such as the one at the race track, it includes parking-lot loops where interested people can drive or ride in the hydrogen-powered, emission-free vehicles.

The cars, from nine automakers, seemed ``really cool'' and ``very interesting'' to Allison Milham, a 21-year-old San Francisco State University student. She came to Albany as part of a field trip for a geology class on energy and environmental issues.

Some of the cars, such as Ford's Focus sedan and Toyota's Highlander sport-utility, closely resemble the gasoline-engine models sold at U.S. dealerships. Others, such as DaimlerChrysler's F-Cell, Nissan's X-Trail and GM's HydroGen3 are based on models sold in other countries, but not in the United States.

The gathered experts touted the benefits of fuel-cell cars, but quickly noted the still-to-be-hurdled challenges.

In fuel-cell vehicles, hydrogen is combined with oxygen to produce electricity. The vehicles produce no tail-pipe emissions, are quiet and eliminate many of the problems associated with gasoline.

But Christian Mohrdieck, director of fuel-cell drive system development for DaimlerChrysler, noted that both technical and cost issues remain to be solved before the vehicles can enter the mainstream.

Vehicle range, hydrogen storage and cold-starting issues are among the technical challenges. Creating a network of fueling stations has only begun. Right now, three hydrogen fueling stations are operating in the Bay Area and three more are planned.

And then there's price, which Mohrdieck described as a ``very, very critical issue.'' Some of these hand-built vehicles cost $1 million or more today. It'll take mass production and engineering improvements to make fuel-cell vehicles cost close to what internal-combustion vehicles cost.

His company predicts that fuel-cell vehicles will become commercially viable in 2012 to 2014, and that by 2015 there might be 100,000 of them on the world's roads.

By 2007, the partnership says, its members will have 300 fuel-cell cars, trucks, SUVs and buses on California roads. Today, about 100 are being tested. Besides automakers, oil companies, fuel-cell manufacturers, governmental agencies and transit authorities such as the Santa Clara VTA are partnership members.

This year's rally, the fourth, is ``a good way to demonstrate progress,'' Weverstad said. ``We're still making incremental improvements -- the costs are coming down, the durability is getting better, the performance is better, the range is better.''

About 20 vehicles are taking part in the Road Rally, including a Chevrolet Silverado pickup truck with two fuel-cell stacks being tested by the U.S. Army. Vehicle range using compressed hydrogen stretches from around 100 miles to nearly 200 miles, depending on the vehicle. GM says its HydroGen3 minivan can go 250 miles when it uses liquid hydrogen.

Rising gasoline prices have given hydrogen and other alternative-fuel technologies more attention recently. Mohrdieck last worked in the United States in 2002 when gas was selling for $1.30 a gallon in Michigan. On this visit from Germany, he said, it was up to $3.30 a gallon.

``That gives you a perspective,'' he said.