AUSTIN - Opening Texas toll roads to free use might ease congestion in certain communities, but the expense would be staggering, officials told state lawmakers Wednesday.

More than $21 billion in debt held by the state and local tolling agencies is connected to toll roads in the state, according to a preliminary analysis by the Texas Department of Transportation. With interest and other costs, these agencies will end up paying $38 billion to erase the debt over the next three decades, based on current projections. The bonds are backed by toll revenues.

Even if the state cashed out later this year, TxDOT director James Bass said a "guess" would be that it would cost around $30 billion.

A final version of the toll road analysis is required by Sept. 30 under HB 2612, passed in the last legislative session. The bill was written by House Transportation Committee Chairman Joe Pickett, D-El Paso, whose committee heard a status update Wednesday. Pickett and other lawmakers, responding to a chorus of critics, have grown increasingly frustrated with what they consider over-reliance on tolling to add roadway capacity.

Even so, "I really don't believe the final dollar amount … to eliminate toll roads is feasible in the near future," Pickett said.

Grand Parkway cited

Opponents of toll roads cheered the analysis as proof the state has relied too much on debt, though many conceded that eliminating the tolls would cause pain as well.

Along with $21 billion in toll-related debt as of Jan. 1, and $10 billion related to partnerships with private firms, TxDOT has $13.4 billion in bonds outstanding related to its own spending. Combined, the $44.4 billion is four times TxDOT's annual budget, which is spent mostly to maintain 195,000 lane miles of roads. The total does not include a $2.1 billion project to add toll lanes along Texas 288, which was finalized after Jan. 1.

Traffic congestion is a problem in many parts of the state, though there is little consensus on the best way to spend transportation dollars to relieve it. At an afternoon hearing, State Rep. Armando Walle, D-Houston, noted that investment in the Grand Parkway, a third ring road encircling the Houston area, might improve some trips but won't cure the region's ongoing traffic problems.

"We have other roads that need help," Walle told TxDOT officials.

In the Houston area, about $5.6 billion in debt remains across five agencies that control toll or managed lanes. Most of the debt is related to the Harris County Toll Road Authority - which operates the region's largest tollway system - and the Grand Parkway, the newest segment of which opened Tuesday.

The state-maintained portions of the Grand Parkway have an outstanding principal amount of $3.11 billion. Paying it back on the current schedules, however, means the state will end up paying $6.45 billion over the next 30 years.

Growing frustrations

On the opposite end, the high-occupancy toll lane system along Interstate 45, U.S. 59 and U.S. 290 managed by the Metropolitan Transit Authority has no debt because the lanes were funded with public money and the tolling is allowed only if it does not affect normal operations for carpools and transit.

Houston area officials have supported tolls for helping to get much-needed projects built long before public funding was available. Despite some pushback to tolling, HCTRA is widening the Sam Houston Tollway - including a $1 billion reconstruction of the Ship Channel Bridge - and planning an extension of the Hardy Toll Road to downtown Houston.

HCTRA projects are totally funded by toll revenue and do not receive money from the state or county. The agency, in fact, generates money for road improvements in the area.

Texans are growing increasingly frustrated by tolling, lawmakers said. Recently, opponents scuttled a plan for toll lanes in San Antonio along U.S. 281.

The San Antonio project also benefited from Prop. 7, a constitutional amendment passed in November that will inject $2.5 billion into highway projects. Prop. 7, and another voter-approved transportation funding windfall, Prop. 1, approved in 2014, both forbid using the money for toll lane development or construction. Both passed by enormous margins.

Supporters of toll roads remain convinced they are an important tool, although they concede some have faced challenges. Vic Suhm of the Tarrant Regional Transportation Coalition, which has supported toll projects in the Dallas area, said the region has been able to use $3 billion in public funds to create $22 billion in projects, notably managed lanes.

"In an ideal world, we would have enough revenue," Suhm said. "But absent, we should preserve the funding tools needed."

Southern portions of SH 130, which connects the Austin area to Interstate 10, were built as part of a concession agreement with TxDOT. The company that partnered with the state recently filed for bankruptcy protection.

'Great system' sought

Though the road remains open and state officials stressed the bankruptcy will not cost the state anything, the lack of use of the toll lanes and financial failure have fueled the arguments of longtime toll critics and galvanized new skeptics.

Weaning the state off tolls would mean a hit for TxDOT's bottom line, but critics of the toll lanes said it is a worthwhile goal.

"We're trying to get back to that great system that we had," toll opponent Don Dixon told lawmakers, recalling the road building of the mid-20th century that helped connect much of Texas. "Get rid of the debt and get rid of the tolls and have a low cost system that everybody can benefit from."

That sounds wonderful, said state Rep. Larry Phillips, R-Sherman, adding: "Let's just find out how to pay for it, that's what I want to know."