The Sonoma-Marin Area Rail Transit board on Wednesday submitted an application for $20 million in federal money to extend the commuter line to Larkspur.

Grants from the Transportation Investment Generating Economic Recovery fund are highly competitive with only about 5 percent of applicants getting money.

But SMART officials say the project to extend proposed service from downtown San Rafael to the Larkspur Ferry terminal — a distance of 2.2 miles — meets the requirements of being nationally and regionally significant.

"We have a strong application," said SMART general manager Farhad Mansourian.

The project has been recognized by the Federal Transit Administration and the regional Metropolitan Transportation Commission for linking its proposed commuter rail system with other transportation networks, Mansourian said.

SMART officials estimate the extension's cost at $40 million. The other $20 million could come from MTC bridge tolls. Jake Mackenzie, a SMART board member and MTC commissioner, said the MTC money could be awarded next month, thus providing matching funds for the federal grant.

"This will end up being a good combination of regional and federal money to complete the southern end of the line," he said. "I believe we are in good shape this time."

SMART has tried and failed six times to get funding from the same Department of Transportation grant program. Last year, the agency applied for a $10million grant for SMART's bike path.

Fifty-two transportation projects received grants out of 585 applications last year. The DOT program awards grants in the fall.

If SMART is awarded a grant, it could complete the Larkspur extension before the system begins operating in late 2016, officials say. The rail authority has money for design and environmental work on the project.

Extending the line to the Larkspur Ferry terminal would provide the $427 million line with bookends at regional transportation hubs. The northern end of the line is currently near the Charles M. Schulz-Sonoma County Airport.

Officials continue to look for funding to extend the line north to Cloverdale.

You can reach Staff Writer Matt Brown at 521-5206 or