Sen. Kirk Watson Sen. Kirk Watson, D-Austin, spoke June 21 about the Texas Department of Transportation's Mobility35 program.[/caption]

The Texas Department of Transportation has been making headway on its Mobility35 program to add between $4.3 billion and $4.5 billion worth of improvements to I-35 in Central Texas.

TxDOT plans to break ground June 29 on I-35 improvements from Stassney Lane to William Cannon Drive in South Austin.

During a news conference June 21, Sen. Kirk Watson, D-Austin, said I-35 in Austin is one of the most congested in the state and improvements are long overdue.

“I-35 really hasn’t had many improvements since the mid-’80s,” he said. “You had little improvement in the ’80s, but for 50 years we haven’t done anything. We finally have a plan. Now we’re in the position to make some changes and make it a smarter road.”

Mobility35, which TxDOT launched in 2011 in partnership with the city of Austin, the Capital Area Metropolitan Planning Organization, and other local leaders and agencies, are planned for 65 miles on I-35 from SH 130 in Georgetown to Posey Road in San Marcos. Improvements will also accommodate bicyclists and pedestrians.

Although some shovel-ready projects are in construction, the rest of the program is in its third phase of implementation—the schematic and environmental phase, which TxDOT expects to complete in 18-24 months. Final design phase will follow and be completed in nine to 18 months. Construction will start after as funding is identified.

This summer, TxDOT will host the first public meetings for environmental studies on three projects in Travis County from RM 1431 in Williamson County to SH 45 SE in South Austin. These projects include studying adding an express lane in each direction as well as additional operational improvements. An online survey for the Central Austin section is available until Aug. 9 at

Travis County improvements are estimated to cost between $1.2 and $1.5 billion, and various other financing options are being explored to cover the remaining cost of the program, according to TxDOT.

Projects under construction have received funds approved by voters statewide in 2014 and 2015, Watson said. So far, $110 million of the funding has been set aside for the Mobility35 program.

In addition to this funding, the Texas Transportation Commission has designated $158.6 million in Congestion Relief Initiative funding to the project, TxDOT Austin District Engineer Terry McCoy said. Other funding will come from CAMPO, state gas tax revenue and local investments.

“[This funding] allows us to put some of the projects on the ground and address some of the specific congestion areas that we experience every day in downtown Austin,” McCoy said. “Travis County is our priority section.”

The main reason for the lapse in the Mobility35 program is a lack of TxDOT funding, Watson said, pointing out TxDOT previously told the Texas Legislature it needed an additional $5 billion annually to “maintain—not fix—congestion,” on Texas roadways.

Watson said the Legislature provided an additional $300 million via Rider 42, which was used to study the 50 most congested roadways in Texas. He estimates about $30 million was set aside for I-35. He said the city of Austin also contributed additional funding. He discussed other funding options at a May 26 luncheon.

Improving I-35

The completed Mobility35 program would improve six of the top 100 congested roadways, including the segment between Hwy. 290 and SH 71, which ranked No. 1 in 2015, according to TxDOT. On that segment during peak daytime hours, TxDOT reported I-35 is congested for six hours daily. By 2040, TxDOT estimates the same segment will increase to nine hours of traffic congestion because the Austin-area population is expected to increase from 2 million to 3.8 million by 2040.

McCoy said the planned improvements are estimated to significantly increase downtown I-35 speeds from 13 to 51 mph during morning peak periods and 9 to 46 mph during afternoon peak periods. The speed estimates of 9 mph and 13 mph reference if improvements were not made under the “no-build” option for 2025.

TxDOT Public Information Officer Kelli Reyna said improvements are also needed for safety reasons. More than 200,000 vehicles travel on I-35, and 86 percent are headed to and from Travis, Williamson and Hays counties.

McCoy said innovative designs are being used for Mobility35, including at the intersections. Projects will include diverging diamond intersections, roundabouts and intersections with median U-turns.

“The ramps worked fine, probably, when I-35 was originally constructed, but they don’t work well now,” McCoy said. “A lot of times they act as impedances, so we’re reducing the number of ramps we have.”

TxDOT is also proposing to modify frontage roads and implement intersection bypass lanes. McCoy gave an example of being able to go under Martin Luther King Jr. Boulevard to bypass the intersection and access 15th Street without being on the I-35 main lanes.

“That’s really localized capacity, similar to what we have in the southbound direction as you exit at MLK,” he said.

Express lanes will also be added “as the corner piece of the program,” McCoy said.

Other aspects of the Mobility35 include improved traffic management systems, new traffic cameras and dynamic message signs to improve communication with motorists and help reduce congestion. The HERO Program, which assists stranded motorists, would also be expanded.

More information about the Mobility35 Program and projects is available at