Regardless of exactly how it happens, it appears taxpayers will pay the price should Texas try to eliminate toll roads.

Frustrated by the proliferation of pay-to-use roadways in Texas, lawmakers continue studying options for abolishing toll roads – specifically those under state control. The price tag for such a move, however, is daunting, based on previous estimates and a deeper analysis discussed last week in Austin.

“I want these communities to see the details,” said state Rep. Joe Pickett, D- El Paso, chairman of the Texas House Transportation Committee.

Pickett, however, called the discussion a “difficult exercise.”

Though officials are still gathering some financial details from non-state tollways, Texas Department of Transportation officials estimate the 23 toll systems in the state have $32.5 billion in debt, payable between now and 2035. During that 20 years, TxDOT – relying on local figures for non-state tollways – estimates toll roads will bring in $74.6 billion, and cost $21 billion to operate and maintain.

The difference, more than $21 billion, is Pickett’s primary concern, he said. If it gives officials opportunity to pay off the roads more quickly that should be the goal.

“If we were to come up with a formula or a plan, we could dedicate the difference between the debt service and the revenue,” Pickett told TxDOT officials.

The starting point might be state-controlled toll roads, he said. Compared to those run by large local tolling agencies such as the Harris County Toll Road Authority and North Texas Tollway Authority, however, the state’s share of tollways is small but growing. Based on the analysis, TxDOT has $6.9 billion in debt service, $3.5 billion in anticipated and an expected $12.7 billion in revenue from toll paying drivers.

The figures, compiled for a May 25 meeting, differ slightly from March estimates. In the current round of figures, TxDOT was unable to include full estimates for the contentious SH 130 toll segments managed by SH 130 Concession Company, LLC from Seguin to south of Austin. The company, citing less-than-expected use, filed for bankruptcy in March. The tollway remains open.

Not counting the 130 segments, another $4.4 billion in debt is related to partnerships the state has with private companies to build tollways, allowed under permission the Legislature gave TxDOT to enter into comprehensive development agreements. One of the most substantial of those is a plan for toll lanes along Texas 288, set to start construction later this year from U.S. 59 in Houston to the Brazoria County line.

Pickett said his goal is to not let these projects perpetuate others, at least in some spots.

“Could we come up with a date when the toll is removed?” Pickett asked. “We would project we would continue tolling these roads, but on this date we would remove it.”

Despite some beliefs to the contrary, that is not how many tolling agencies in Texas operate, including HCTRA. The agency can continue carrying debt from project to project, per the referendum voters passed in 1983 creating the agency. All of the debt is pooled, so projects are not “paid off” individually, but raise revenue to pay off bonds and then borrow money for the next tollway or to widen the existing ones.

The system has enjoyed long-time support from county officials, and some drivers facing increased congestion as development in western and northern Harris County continues.

From fiscal 2011 to fiscal 2015, which ended Feb. 28, 2015, HCTRA’s annual toll revenues increased from $481 million to nearly $689 million. Over the five years, the toll authority brought in almost $2.9 billion.

Within the next four years, officials plan to begin $2.1 billion worth of construction, notably replacement of the Ship Channel Bridge along the Sam Houston Tollway and extension of the Hardy Toll Road within Loop 610 to the Houston’s central business district.

That method of collecting and expanding, however, has infuriated some drivers, who feel they’ve paid many times over for roads, Pickett said.

“There are a lot of people who hate tolls,” he said.

There's also a limit on what TxDOT can do to slow them down. Though voters have approved roughly $3 billion in new money for highways, none of it can be spent on toll roads. While that keeps TxDOT from adding more tollways, it also means they can't use the money to end them, either.

"New money can't be spent on toll roads, and we have been directed not to supplant," TxDOT Director James Bass said.

Pickett in the past has predicted lawmakers will at least discuss an exit scenario for toll roads when the Legislature reconvenes in Jan. 10.

"We could start picking them off," he said last week, reiterating the need to at least research ending them. "We need to do that on at least the tolls the state of Texas has control over."