SAN RAFAEL -- The North Bay's upcoming passenger-rail system could be inching closer to San Francisco Bay, after the Transportation Authority of Marin requested new regional funding that would help extend Sonoma Marin Area Rail Transit from downtown San Rafael to the Larkspur ferry terminal.

The $11.4 million in funding from the Metropolitan Transportation Commission would help bring SMART closer to embarking on the $40 million extension, with up to $3 million dedicated to a permanent rail crossing at Andersen Drive in San Rafael, according to an announcement from Petaluma-based SMART.

Connecting SMART to the ferry at Larkspur was a key topic in the sales tax measure campaigns to fund the rail line.

MTC money for the Larkspur extension would come from Regional Measure 2 of 2004. By increasing bridge tolls $1, the measure created a pot of funding for projects that relieve traffic congestion throughout the San Francisco Bay Area. The MTC administers those funds in the Bay Area, along with other allocations from state and federal sources.

The SMART extension is one of two projects eligible for Regional Measure 2 funding in Marin County. The other is a bridge to improve access to the Larkspur ferry and reduce congestion on the Richmond-San Rafael bridge approach.

The MTC will consider the funding request at a future meeting. It would be the second of two recent funding allocations that have brought the extension closer to reality, following a $2.5 million federal grant to fund engineering.

SMART is currently expected to begin operating on a nearly 40-mile segment between San Rafael and Santa Rosa in late 2015 or early 2016. If sufficient funding is identified, the system will ultimately operate on a 70-mile segment from Cloverdale in northern Sonoma County to Larkspur in Marin County.