Weeks before lawmakers return to the Capitol for what's shaping up as a difficult 2017 session, one of their signature goals is facing serious challenges.

A special committee that toured the state for months to craft plans for shoring up Oregon's transportation system has yet to agree on what a multimillion-dollar proposal should look like. They don't know which projects it will include. They can't say how those projects will be financed.

They also aren't sure they can guarantee state officials will spend the money wisely. Instead, they're waiting for an audit that will tell them whether the Oregon Department of Transportation can manage a larger budget.

Those concerns bubbled from interviews with lawmakers and during a hearing last month where legislators aired a long list of priorities alongside worries that reaching a complicated deal could take months. Because a deal would likely include a gas tax increase, any package would need bipartisan support.

"It is troublesome that so much time has elapsed describing the problem," said Sen. Betsy Johnson, D-Scappoose, a key voice on transportation issues, "and we are still without a working draft of a bill."

Some of the problems that plagued a much-hyped plan two years ago -- chiefly, partisan disagreements over clean fuel standards -- may resurface this year. Lawmakers may also find tension as they face another looming problem: how to plug a $1.7 billion budget hole.

And even if lawmakers do manage a deal, interest groups could rebel over any tax hikes, sending the package to voters.

Mixed priorities

Transportation officials have warned lawmakers for years about the consequences of failure. Without improvements, bridges and overpasses could crumble in a major earthquake. Without expanded transit options or new roads, they say, traffic in the Portland metro area will worsen, adding to safety risks and the rising cost of moving freight.

Maintaining existing infrastructure would cost hundreds of millions of dollars more per year, officials say - not including the cost of expansion.

All the talk has lawmakers eager to find fixes. "They're champing at the bit," said Sen. Lee Beyer, D-Springfield, who co-chairs the special 14-member transportation committee, which built its list of priorities after months of hearings across Oregon.

That work may be at risk of sputtering.

Not having a whittled-down list of projects is "a major problem," one of the committee's vice-chairs, Rep. Cliff Bentz, R-Ontario, said during last month's meeting.

In the same meeting, Johnson, the Senate Democrat, asked if committee leaders were privately crafting legislation without the full 14-member committee. Johnson was among a handful of members who worried they wouldn't be consulted before a final project list is assembled.

Johnson's vote will likely be needed to pass whatever legislation emerges. Democrats lack the three-fifths supermajorities required to pass taxes, and Johnson, at times, has sided with Republicans.

Two years ago, select lawmakers and Gov. Kate Brown's office worked behind closed doors to build a transportation deal. That deal fell apart once it went public, with lawmakers balking over fuzzy numbers and proposed changes to the state's clean-fuels program.

Legislative leaders have called for this year's deal to take shape in public. Beyer said in an interview that there have been no backroom negotiations so far.

"In an open, public session, we're going to try and construct the package," he said. "No one's ever tried to do that before."

During last month's hearing, however, Rep. Caddy McKeown, D-Coos Bay, who chairs the group with Beyer, counseled patience. She said committee leaders -- two Democrats and two Republicans -- would likely work out a framework they would then bring to committee members.

Beyer said he and the committee's leaders are committed to crafting a transportation package "in a bicameral, bipartisan way."

Funding

Who pays for transportation fixes is another challenge.

Lawmakers say every revenue option should be considered, including increases to the gas tax and license and registration fees, tolls on new highways, borrowing money, and new fees on bicycles and electric or high-mileage vehicles.

Bob Russell, a lobbyist for the Oregon Trucking Association, called the ultimate dollar amount "the elephant in the room" during last month's hearing.

Members of the Oregon Transportation Commission, which oversees the state transportation department, proposed spending an additional $1.1 billion every two-year budget cycle.

Legislators say they're looking at raising revenue because current gas tax returns are dwindling. The federal government hasn't raised the nationwide gas tax in over two decades, and higher-mileage vehicles on the road have cut revenues further.

But cutting a deal on the gas tax looms as a huge political lift, especially in a legislative session where Democrats and Republicans are already expected to disagree over tax reform and spending cuts.

Republicans in 2015 refused to back a gas tax increase because they saw Oregon's low-carbon fuel standard - which requires petroleum providers to mix their gas with ethanol or biodiesel, or buy credits to offset pollution - as a hidden gas tax.

Brown warned lawmakers in private remarks reported by The Oregonian/OregonLive last year that repealing the fuel standard is off the table. A spokesman for the governor said Friday that Brown will seek a bipartisan solution. Karmen Fore, Brown's transportation policy advisor, declined an interview through a spokesman.

Beyer said the low-carbon fuel law is "a skin on the wall for environmentalists," though legislators must be open to alternatives.

House Republican Leader Mike McLane, R-Powell Butte, said Friday his caucus remains "concerned" about the clean fuels law, which could raise gas prices from four to 19 cents a gallon over 10 years.

"Opportunities exist to come up with a compromise that will allow us to fully fund and repair our infrastructure and cut carbon emissions," McLane said, "and I hope Democrats will join us in that effort."

"Meaningful changes" to the low-carbon fuel standard will be a "critical" part of a transportation deal, said Senate Republicans spokesman Jonathan Lockwood.

The low-carbon fuel law has also been a top target of fossil fuel lobbyists. In 2015, petroleum groups filed three ballot measures to repeal it. That effort was shelved, but Paul Romain of the Oregon Fuels Association said at the time that lawmakers would be asked to repeal the clean-fuels standard in 2017.

Asked on Thursday whether petroleum interests would take a transportation package to the ballot, Romain said, "It depends what's in the deal - whether it makes anybody mad or not."

Accountability

Lawmakers from both parties are also struggling with how much they trust the state's transportation department to manage an influx of cash.

From doomed plans for a new Interstate 5 bridge over the Columbia River to an expensive Highway 20 realignment near Eddyville, the agency has presided over a list of delayed, over-budget or incomplete projects.

Brown, who named transportation a top priority, promised an audit of the agency, which operates on a two-year budget of $3.7 billion, after lawmakers raised concerns about its management two years ago.

The effort got off to a rocky start. Consultant John Craig won $350,000 to do the review, only to have his contract rescinded when lawmakers complained that Craig, who ran the agency's outsourced bridge repair program for six years, would grade his own work.

Another contractor is set to return a preliminary diagnosis to legislators next month. The review now comes with a $1 million price tag, and lawmakers want their money's worth.

"There's a lot of people who question how (the transportation agency) is structured - whether they're efficient or bloated," Beyer said. "We went to great pains - I pushed pretty hard - saying we need to get an honest-to-god audit."

Bentz called the review "extraordinarily important."

"We have a bunch of ideas but we haven't sat down and really decided what to get done," Bentz said. "We have a really, really challenging path in front of us."

-- Gordon Friedman

503-221-8209; GFriedman@Oregonian.com