Sonoma-Marin Area Rail Transit officials on Wednesday rejected a Marin County grand jury recommendation to defer building a pedestrian and bicycle lane as a way to deal with a funding deficit that jeopardizes the ability to open the rail line on time.

SMART is undertaking a review of its construction costs and revenues, however, and will make a decision in the fall about how much of the 70-mile line can get built and when.

"The whole board is still committed to the project as it was passed," said San Rafael Mayor Al Boro, a SMART board member. "As we get closer to implementation, we will have to make choices."

Measure Q, which received 70 percent of the November 2008 vote in Sonoma and Marin counties, promised a rail line and accompanying pedestrian-bicycle path from Cloverdale to Larkspur, a distance of 70 miles.

The line is being financed by a quarter-cent sales tax that was estimated to raise $890.7 million over 20 years. With the recession eating into sales tax revenues and construction costs expected to have risen, SMART has projected it will be $155 million short of the funds necessary to open the line in 2014.

The Marin County Grand Jury in its report released June 25 recommended SMART defer building the $91 million bike path until alternative funding could be found.

In the same report, the grand jury also recommended that SMART broaden the responsibilities and authority of its citizens advisory committee and reconsider what the grand jury termed excessively generous retirement benefits for the SMART staff, which now numbers 14.

SMART's executive committee on Wednesday, in formulating a response to the grand jury, said it would add an annual review of the rail agency's strategic plan to the advisory committee's responsibilities. The committee said it doesn't consider the retirement benefits generous, but they would be reviewed by the executive committee.

The bike path, however, is the most contentious issue and one SMART officials were most adamant about being retained, at least for now.

"As the grand jury notes, Measure Q defined the SMART project to include a passenger train and an adjacent bicycle-pedestrian pathway. Measure Q was supported by 70 percent of Marin and Sonoma voters," a proposed response by SMART states. "Until SMART adopts a Program Implementation Strategy, it is premature to 'defer' any part of the project."

The ability to ride a bicycle on a path to a station is expected to help drive ridership and was popular with voters, officials said.

"Bikes will be a significant feeder to the trains," said Barbara Pahre of Napa, a SMART representative from the Golden Gate Bridge District. "We are putting in bike capacity in the trains; we are putting bike capacity in the stations."

Windsor Councilwoman Debora Fudge, SMART's chairwoman, said she has not not received any suggestions from the public to eliminate the path. "The comments that have been made to me have been positive on keeping the bike path," she said.

Allen Tacy of Petaluma, chairman of the Friends of SMART, said the projections for the use of the bike path are higher than for the trains.

"The use of the trail is expected to be twice the train, 55,000 who will use the trail and 26,000 who will use the train," Tacy said. "It is a real significant feature."