When will I-35 road construction start in downtown Austin?

TxDOT is expected to receive a final verdict on its draft environmental impact statement in August, a required document that outlined all the potential environmental impacts related to the project. Once they receive the federal thumbs up on that draft EIS, the state transportation agency can move forward toward construction.

AUSTIN (KXAN) -- With the Texas Department of Transportation poised to receive final federal clearance for its Interstate 35 Capital Express Central project next month, Austin District project heads have laid out the next steps for the eight-mile project.

TxDOT is expected to receive a final verdict on its draft environmental impact statement in August, a required document that outlines all the potential environmental impacts related to the project. Once they receive the federal thumbs up on that draft EIS, the state transportation agency can move forward toward construction.

During a July 19 Austin Downtown Commission meeting, TxDOT's Mobility35 Program Manager Tommy Abrego delivered a presentation on the $4.5 billion planned expansion. Pending federal approval of the EIS draft, TxDOT is expected to begin construction on a drainage tunnel in 2024.

Later on in 2026, Abrego said road construction is anticipated to begin, with that construction timeline lasting roughly six to eight years, depending on conditions.

Abrego said the eight-mile I-35 Central project -- running from U.S. Hwy. 290 East to SH 71 and Ben White Boulevard -- will include:

• Addition of two managed, non-tolled high-occupancy vehicle lanes in each direction
• Removal of the upper decks
• Reconstructed ramps, bridges and intersections
• Frontage road improvements, including boulevard-style frontage lanes with lowered speed limits
• Enhancements to pedestrian and bicycle infrastructure

The expansion proposes a Lady Bird Lake pedestrian bridge project, as well as single-point urban interchanges at Airport Boulevard and Riverside Drive. Those transportation intersection designs incorporate a single traffic signal to enhance the number of vehicles passing through an intersection at any given time, Abrego added.

Throughout the duration of the project, Abrego said TxDOT will maintain two to three lanes in each direction for the entirety of construction, in an effort to minimize traffic impacts.

As part of project efforts, TxDOT is working alongside the City of Austin's Our Future 35 program, which aims to fund the creation of deck plazas on top of the lowered highways. Those deck plazas -- similar to Klyde Warren Park in Dallas -- can accommodate a slew of public uses, including parks and open space, retail, residential buildings as well as other city-led amenities.

Susan Daniels with the Austin Transportation and Public Works Department told commissioners July 19 Our Future 35 is continuing its analysis of the weight capacities for these caps and, in turn, what can be built. Over the next 18 months, she said the program will flesh out more fully what those capacity and amenity opportunities look like and how to fund them.

Since funding for the decks isn't incorporated into TxDOT's $4.5 billion project budget, Daniels said Our Future 35 is getting creative in evaluating possible opportunities. Those options include voter-approved and non-approved debt programs, public-private partnerships, naming rights, sponsorships and philanthropic collaborations.

"The quick answer is it's going to take a lot of different sources," she said.

To date, Our Future 35 has been awarded more than $2.6 million in federal dollars, with project leaders eyeing other possible federal grant opportunities.

In August and September, Daniels said Our Future 35 will host several open house tours of the program's ongoing work, as well as launch focus groups for residents to participate in. Those groups will focus on key project highlights, such as:

• Active transportation and safety
• Sustainable design
• Accessibility
• Design and architecture
• Arts and culture
• History and equity
• Environmental justice

Commissioner Amy Mok said she hopes the work on Our Future 35 can help revitalize the I-35 corridor, while also addressing segregation efforts the highway has historically inflicted on eastside residents.

"This is a history-making project," Mok said. "It needs to involve, I think, our entire city, to correct all the bad policy that disconnect our community in the past. We are giving a second chance to to reconnect and to transform our city."