The SFSU study used data collected for a master's thesis submitted in early 2006 and found an average of 40 percent of tolls in the Bay Area were paid electronically -- 30 percent fewer electronic toll payments than bridges in New York, New Jersey and Illinois, the study's authors found.
The one exception is the Golden Gate Bridge, which offers a consistent discount to FasTrak users, and has a similar peak usage pattern -- around 70 percent of toll payments made electronically -- to that on bridges in the other states studied, the study noted.
Bridges in those other states included in the study offer consistent discounts of between 11 and 50 percent to drivers paying tolls electronically.
"Temporary discounts do result in spikes in FasTrak adoption," said one of the study's authors, Professor Sanjit Sengupta. "But only a small section of the population is aware and takes advantage of such promotions. To change the behavior of large numbers of drivers across the Bay Area will require sustained application of economic incentives."
Other incentives transportation agencies could offer to persuade drivers to adopt FasTrak include extending FasTrak lanes at the Bay Bridge further back in the maze during the week; decreasing the number
The Metropolitan Transportation Commission and the Bay Area Transit Authority have been trying to encourage motorists to sign up for FasTrak toll tags by increasing the number of FasTrak-only lanes on some bridges and in January offered a $1 discount to drivers on the region's seven state-owned bridges.
BATA spokesman Rod McMillan said subscription rates have improved in the last year and that some of the increase is directly attributable to a FasTrak discount program offered in January.
There are some 625,000 FasTrak account holders in the Bay Area, which equates about 900,00 toll tags in circulation, McMillan said.
"Now we're starting to see the percentage uses on the bridges go up," he said.
Bridges in the region that just under a year ago saw between 32 and 45 percent of peak commute period tolls paid electronically now see between 40 and 51 percent of drivers using toll tags, McMillan said.
Some 52 percent of evening commute drivers on the San Francisco-Oakland Bay Bridge pay tolls using FasTrak compared with 44 percent in March last year, he said.
Morning peak periods run from 6 a.m. to 10 a.m. and evening peak periods are from 3 p.m. to 7 p.m., he said. The peak morning commute on the Bay Bridge is 5 a.m. to 10 a.m., he said.
McMillan said BATA is aware of the incentives discounts provide but that because bridge tolls go toward mandated regional bridge improvement projects, there is little room in the budget for discounts.
Earlier this year toll authorities expanded the number of outlets selling FasTrak tags to include more than 60 Safeway and Costco stores.
The study was published in the winter 2007 edition of Transportation Journal and was authored by Professor Sanjit Sengupta, Assistant Professor Ramesh Bollapragada and Master of Business Administration graduate Hector Bedolla. Bedolla, who graduated in May 2006, gathered the research data for the paper for his MBA thesis.