A proposition on the Nov. 4 ballot could help repair the state's ailing highway system, including heavily traveled Central Texas roads.

"We've got enough work [on I-35] to last a lifetime," said Will Conley, chairman of the Capital Area Metropolitan Planning Organization, which is responsible for coordinating transportation projects in Central Texas. "It's all of the above: It's adding lanes. It's redesigning ingress and egress for higher levels of safety and mobility. It's a combination of small to large projects and everything in between."

Proposition 1 would amend the Texas Constitution so as to divert some of the taxes paid by the state's oil and gas companies to the State Highway Fund, which helps fund the Texas Department of Transportation. The state comptroller's most recent estimate pegs TxDOT's potential windfall from the proposition's passage at about $1.7 billion in the first year alone. State Rep. Tony Dale, R-Cedar Park, was a co-author of Proposition 1.

"We can redirect some of this money without having to raise taxes to provide billions of dollars," Dale said. "It's a good start to try to solve our transportation funding issues."

Currently 75 percent of the severance tax—essentially a production tax paid by oil and gas companies—goes to the state's Economic Stabilization Fund, also known as the Rainy Day Fund. If Prop. 1 passes, 37.5 percent of the tax would continue to go to the Rainy Day Fund, and 37.5 percent of the tax would go to the SHF. The remaining 25 percent would continue to help fund the state's education system.

The revenue would have an assortment of strings attached including a provision barring the money from being used for construction of toll roads and a mandate for TxDOT to identify $100 million of cost savings.

Scott Haywood, a spokesman for Move Texas Forward, an organization created by former TxDOT commissioners dedicated to lobbying for increased funding for Texas roads, said the measure would help TxDOT bridge its estimated $5 billion annual shortfall for maintaining existing roads and paying down its debt.

How we got here

Haywood said most of the state's transportation revenue sources have remained steady since the early 1990s, but costs and congestion have soared.

Currently 20 cents of every gallon of gas purchased in Texas goes toward the state's fuel tax. Of that amount, 5 cents helps fund the state's education system, and 15 cents goes toward the SHF. The fund is also bolstered by the state's vehicle registration fee, among other sources. In 2012 the fuel tax provided $2.3 billion for the SHF, according to the state Legislative Budget Board.

Additionally, in 2013 the average fuel economy of cars sold in America reached an all-time high of 24.9 miles per gallon, according to a study by the University of Michigan Transportation Institute.

"There's no doubt that fuel efficiency in vehicles has increased over the years; that does have an impact on gas tax collections," Dale said. "We are also adding more and more vehicles on the road all the time because of the increased population."

According to a 2007 study commissioned by TxDOT entitled "Accounting for Fuel Efficiency in Texas Fuel Tax Revenue Estimations," the department could lose out on $86 billion in fuel tax collections because of assumed increases in the fuel efficiency of vehicles between 2007 and 2031. To overcome that deficit, the study found TxDOT would need to raise the state fuel tax665 percent to $1.53 per gallon of gas.

To keep up with the state's growth, Texas voters approved bond debt issuance for road infrastructure in 2001, 2003 and 2007 totaling $17 billion, Haywood said. In all, stagnating revenue sources and mounting debt has left the state with a cash-strapped department, he said.

"When you look at the next [two years], we have a significant drop-off in what the department can do from a transportation standpoint," Haywood said.

Identifying savings

If Prop. 1 passes, TxDOT must identify $100 million of savings. It is not clear how those savings will be identified, though.

Dale said TxDOT could reduce its costs by working more with private industries. The department could own fewer vehicles and find ways to improve equipment maintenance or fuel efficiency, he said.

TxDOT could save funds by transferring maintenance of state roads to city governments. In Cedar Park, Assistant City Manager Sam Roberts said the city has an agreement with TxDOT to operate traffic signals on state highways within the city, but has had no discussions with TxDOT about maintaining state roads. Leander City Manager Kent Cagle said that only after the city of 36,000 residents exceeds a population of 50,000 residents would Leander leaders begin to maintain signals on state highways in the city.

Fuel for growth

Dale said that in 2013 when legislators approved putting the proposition on the ballot, experts estimated the first year of tax redirection would generate about $800 million for road projects. But the state's energy sector growth has fueled even higher state revenues than expected, and experts now believe the amendment could in its first year generate $1.7 billion in funding for roads.

"Road projects are exceedingly expensive," Dale said. "$1.7 billion is just a start to [fulfill] our needs."

Some state leaders have proposed dedicating a portion of the state's 6.25 percent vehicle sales tax to the SHF.

"The state economy is still very strong, and we've done a good job of keeping the economy going," Dale said. "Anything we can do to get more state dollars to improve the commute times and the quality of state roads, I'm for that."