OAKLAND  (AP) — San Francisco Bay area officials are mulling the idea of charging motorists a tax on every mile they drive in the nine-county region as a way to raise money for roads and public transit while reducing traffic and pollution from car emissions.

Members of the Metropolitan Transportation Commission and the Association of Bay Area Governments were scheduled to vote Thursday night on whether to approve a long-range study on the merits of imposing a Vehicle Miles Traveled tax.

Under a proposal still in its early stages that could take a decade or more to be launched, drivers would be required to install GPS-like odometers in their vehicles and pay from less than a penny to as much as a dime for every mile driven.

Commission spokesman Randy Rentschler acknowledged the concept could prove a hard sell with Bay Area residents, who would likely resist both the travel tax and the government-mandated tracking devices.

"We're not interested in where they go. We're only interested in the amount they travel," Rentschler told radio station KCBS. "But for some folks, that's a distinction without a difference. Anytime you talk about getting information from people, whenever that conversation comes up, it's another hurdle you have to overcome."

Mileage taxes already have been subjected to pilot studies in Atlanta and several communities in Oregon and Washington state. Drivers who were given a sum of money and then had amounts deducted based on how much they drove logged fewer miles, according to the San Jose Mercury News.

Based on current Bay Area driving patterns, a mileage tax could raise up to $15 million a day, the Mercury News said.

The two regional agencies are considering the tax as part of a broader, 25-year transportation and land-use plan to accommodate the 2.1 million new residents who are expected to reside in the Bay Area and to curb greenhouse gases. Other ideas floated so far include raising bridge tolls during rush hour, creating more carpool lanes, and funding public transportation options in counties north and east of San Francisco.

The long-term plan is scheduled to be completed in December and presented for a vote in April.