SANDPOINT - Idaho lawmakers considering increasing the gas tax and vehicle registration fees to overcome a shortage of available highway funding contend it's too soon to say how much those increases could be.

"We don't know for sure," Sen. John McGee said during a meeting of the Bonner County Area Transportation Team on Wednesday.

It's also unclear if such increases will be among the recommendations to Gov. Butch Otter, who has the final say on which funding alternatives will advance for further consideration by the Legislature.

Proposals to raise the gas tax and registration fees ultimately found no traction in Boise a couple of years ago.

But McGee, chairman of the Senate Transportation Committee and a member of the Governor's Task Force on Modernizing Transportation Funding, is not without hope that a solution can be found to the Idaho Transportation Department's funding struggles.

"Ultimately, I'm optimistic that we can come up with a plan to fund our roads," said McGee, a Republican from Caldwell.

Along with hiking the gas tax and registration fees, the gubernatorial task force is considering recommending vehicle-miles-traveled taxes and a range of local option taxes.

A vehicle-miles-traveled tax for non-commercial traffic is the subject of a pilot program in Oregon, but Sen. Shawn Keough concedes such a tax might be ahead of its time in Idaho, a state which prides itself on limited government intrusion in people's lives.

"It's a huge, different mindset for all of us," said Keough, a senior member of the transportation committee and a task force member.

McGee and Keough also concede selling a new or boosted tax in a down economy can be a challenge, especially when not all lawmakers agree there is insufficient funding for Idaho's highways.

There are also misconceptions among the public that lawmakers can simply tap the state's general fund or crimp funding for education or health services to solve the highway funding riddle. State transportation funding comes mostly from registration fees and fuel taxes, the latter of which is being affected by the presence of more fuel-efficient vehicles.

However, Keough said triggering a modest gas tax to coincide with a strengthening economy could be palatable to the public. She pointed out that a small gas tax increase was triggered through a state program to rid Idaho of faltering underground gas storage tanks and the hike went largely unnoticed.

The task force's recommendations are due on Otter's desk in December.

"I think this issue will be addressed next session, but I don't know where it's going to go," state Rep. George Eskridge said during the meeting.