CHEYENNE -- In a push to secure new highway funding sources, state transportation officials are exploring whether commercial truckers should be required to pay tolls to use Interstate 80.

The Wyoming Department of Transportation has commissioned a study on the topic. The study will also examine public-private highway ownership partnerships, said Doug McGee, spokesman for the agency.

It's part of an effort to explore alternative ways to pay for I-80 maintenance in light of flat or decreasing federal highway funding and rapidly escalating numbers of commercial trucks on the deteriorating interstate highway.

"What we are really talking about is tolling trucks. That is the initial discussion," said Sen. Michael Von Flatern, R-Gillette, chairman of the Transportation, Highways and Military Affairs Interim Committee, which is helping to coordinate the effort.

"The main reason is that the feds are cutting back on their support for the states and also saying, 'You better think outside the box on highway funding,'" he added.

Von Flatern, who led an unsuccessful bid last year to raise the state gasoline tax, said it's early in the process, but he estimates that commercial truckers could eventually pay from $40 to $80 to cross the roughly 400-mile width of Wyoming on I-80.

He said that price stacks up well against other states with pilot tolling programs on their interstates, and it could mean money to pay for vast safety improvements on I-80 -- including the possibility of an added lane in both directions.

Early estimates suggest that revenue from tolling might generate the entire $6 billion to $8 billion the state says it needs to maintain and expand I-80 in Wyoming over the next 20 years, Von Flatern said.

If that is the case, it would mean more money for other state interstates and highways, which now compete with I-80 for funding.

"That's a big benefit," he said.

Von Flatern said changes in federal rules are allowing states to consider highway funding options they never had before, including tolling.

In the past, he said, strict federal rules and massive financial penalties all but prevented states from collecting tolling revenues on federal interstate highways.

"In previous years, the state would have basically had to pay the federal government back for every penny it ever spent on I-80 since its inception" in order to create a tolling system, Von Flatern said.

But a shortage of federal highway dollars, which cover most of the nation's highway maintenance costs, has resulted in a loosening of some restrictions, he said.

"By them loosening up those restrictions on tolling, they're essentially saying, 'Here's one option,'" Von Flatern said.

Von Flatern added that he has heard some positive feedback from a national trucking group whose companies lose big bucks when I-80 closes because of crashes or poor weather. While those groups generally oppose tolling on existing roads, they might be less resistant if the toll funds would pay for improvements that could keep traffic flowing on the highway, which is a main artery for the nation's shipping industry.

Sheila Foertsch, managing director of the Wyoming Trucking Association, said her organization generally opposes tolling on existing roads. However, she will wait until she hears more about this proposal, including how the tolling revenue would be spent, before weighing in.

"We really don't want to take a position until we know what they are planning," Foertsch said.

PB Americas, an international consulting firm with offices in Denver, will conduct the I-80 tolling study. A company representative will discuss its plans when the Transportation Committee meets in Gillette on May 21 and 22.

Von Flatern said he hopes some results will be ready in time for his committee's July meeting, when he also hopes to have draft legislation in hand authorizing WYDOT to proceed with a tolling plan.

I-80 is by far the state's busiest highway. More than 12,800 vehicles trace the interstate at its busiest point in Wyoming each day, and about half of them are big rigs, mostly from out of state.

WYDOT in 2006 estimated that the number of trucks on I-80 will grow by 60 percent over the next 20 years, to more than 12,200 semitrailers a day, or about one truck every 12 seconds.

A fully loaded semi weighs tens of thousands of pounds and can deliver the same highway strain as 4,000 or 5,000 passenger cars, according to WYDOT figures, which the agency says are conservative.

State transportation officials insist that without a major change in the funding system, I-80 will drain millions of dollars from the state highway system in coming years, even as the interstate continues to deteriorate.

Reach capital bureau reporter Jared Miller at (307) 632-1244 or at {M3jared.miller@trib.com.