The face of the Cloverdale-to-Larkspur rail commuter line likely will be a sleek, American-style, heavy-rail car that exists only in the imaginations of engineers.

Although heavy-rail cars are more costly and less efficient than lighter, European-designed cars, they would meet Federal Railroad Administration and Buy American requirements that otherwise could delay delivery time.

"It erases all regulatory concerns and improves the likelihood of achieving project implementation," said Bill Frandsen of LTK Engineering, a consultant for the Sonoma Marin Area Rail Transit district.

Still, there was a more basic reason that a SMART subcommittee this week recommended to the full board that the agency choose heavy-rail cars over light rail. Members were told that manufacturers are willing to design and build only those heavy cars that will meet the Environmental Protection Agency emission standards that take effect in 2011. Manufacturers have said they would not redesign and build the lighter European-style cars to those EPA specifications because they don't believe there is a market for them in the United States, Frandsen said.

SMART has budgeted $88 million to purchase "diesel multiple units," which are self-propelled cars that can be configured to include restrooms, kiosks for food and drink, and room for bicycles.

The heavier self-propelled cars typically weigh about 800,000 pounds and are allowed by federal regulators to run at the same time of day as regular freight trains, removing the need for SMART to ask for a waiver.

However, the heavier cars cost $8.5 million, compared with $7 million for the lighter cars, and use 37 percent more fuel.

The lack of an option for light rail was a major disappointment for the SMART operations committee, which preferred the ride quality, cost and fuel savings of the lighter cars.

"The look and feel of these trains when people get on them will be their first impression," said Carol Russell, a committee member. "Are they going to get to work with a reasonable ride?"

Committee Chairman Charles McGlashan of Marin County was critical of the ride quality of Portland's heavy-rail vehicles.

"It was like riding in a truck," he said.

Light-rail train advocate David Schonbrunn told the committee that the heavy-rail car is a step backward and the decision should be delayed.

"You have gotten a very incomplete report. I really don't believe the manufacturers (of light-rail vehicles) will abandon the American market," Schonbrunn said, referring to the consultant's report.

The committee reluctantly sent the recommendation to the full board for consideration Wednesday, but expects that the eventual specifications will require consideration of cost, fuel economy, customer support and equipment design.

"We will expect something that rides a whole lot better," McGlashan said.

Lillian Hames, SMART's general manager, said the ride of the cars in the Oregon Tri-County Metropolitan Transportation District is not a fair representation.

Those cars were made by Colorado Railcars, which went bankrupt as the cars were being delivered. Better cars can be expected from an international manufacturer.

"Cars made by 12 guys in a garage outside of Denver is a lot different than you would get from a major manufacturer," Hames said.

The manufacturers that have indicated an interest in building the cars have plants in the United States that would meet the Buy American requirements of the Federal Transit Administration, Frandsen said.

The cars would be built to meet the new EPA requirements for the cleaner engines that take effect in 2011, while those same requirements don't take effect in Europe until four years later.

There currently are no heavy-rail vehicles being built with those new engine systems, but there are several manufacturers who have said they will do so, including Siemens, which has a plant in Sacramento.

Construction time is expected to take two to three years, making it necessary to choose a train style now, Hames said.

"The vehicle decision is the most important decision and the most complicated decision," Hames said. "But if we don't have a contract for specifications by August, we can't commit to starting service in November 2014."

The recommendation will be discussed by the SMART board at 1:30 p.m. Wednesday in the council chambers at San Rafael City Hall.

You can reach Staff Writer Bob Norberg at 521-5206 or bob.norberg@pressdemocrat.com.