Bonds sold by the Sonoma-Marin commute rail agency are rated by financial analysts as stable investments, but still are graded below other Bay Area rail systems because the trains are not yet running.
Fitch on Monday rated the Sonoma-Marin Area Rail Transit District at A and Standard and Poor's on Tuesday gave SMART a rating of AA.
In comparison, Fitch gave AA ratings to the Bay Area Rapid Transit District (BART) and to the Santa Clara Valley Transit Authority.
"They are more established systems," said Scott Monroe, an analyst for Fitch in San Francisco. "Since SMART is new, and has yet to construct the system, SMART took a conservative approach to cost, tax revenues, ridership and farebox revenues," Monroe said.
However, Fitch is also taking into consideration what it considers some negatives, such as a low percentage of ridership compared to the number of workers in Sonoma and Marin counties and a low farebox recovery ratio.
SMART told analysts that it expects to carry 3,000 riders a day and that farebox revenue is forecast to be 22.9 percent of operating costs.
In San Diego, the Coaster rail system had a farebox recovery of 39.6 percent, but the Sprinter had 21 percent for the six months ending in January. The Santa Clara Valley Transit Authority had a farebox recovery rate of 15.7 percent in 2011.
SMART is developing a fare schedule that is based on the length of the trip. In it's 2009 strategic plan, SMART estimated that the average one-way fare would be $4.50.
SMART General Manager Farhad Mansourian said forecasts provided to analysts are purposefully conservative and have been reviewed by the Metropolitan Transportation Commission.
Standard and Poor's analysts give SMART bonds a AA rating, based on the strength of the quarter-cent sales tax that will be used to repay the bonds.