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I-35 expansion through downtown Austin gets final green light

An aerial view of I-35 with Austin's downtown skyline in the background.
Nathan Bernier
The I-35 expansion from Ben White Boulevard to U.S. 290 East is being broken into six smaller projects. Completing them all will take about 10 years, TxDOT estimates.

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The state's contentious plan to make the biggest road in Central Texas even bigger has cleared a major bureaucratic hurdle, paving the way for the historic expansion of I-35 from Ben White Boulevard to U.S. 290 East.

The Texas Department of Transportation issued a final environmental impact statement and record of decision on Monday. The documents detail the $4.5 billion highway project and outline TxDOT's efforts to lessen its sweeping impacts on the densely populated areas next to the interstate.

"This is a major milestone for us," Tucker Ferguson, TxDOT Austin District engineer, said. "This sets the roadmap for getting our final designs put together and ultimately going to construction."

The newly released documents reveal small changes TxDOT made to highway plans and mitigation efforts, with more changes possible in the coming months. The final designs won't be nailed down until major construction contracts go to bid, which is expected to start early next year.

Some of the tweaks include:

  • A new elevated bicycle and pedestrian bridge at 15th Street
  • $100 million on "aesthetic enhancements" with an emphasis on east-west bridges over the interstate
  • $9.4 million in funding for CapMetro to maintain bus service during construction
  • A new app to notify the public about construction closures
  • A community advisory committee for project updates and feedback
  • A new noise barrier between I-35 and community gardens near Festival Beach

Many of the changes had already been revealed in a letter by Mayor Kirk Watson that some council members publicized earlier this month.

But the mitigation measures aren't much more than window dressing to opponents concerned about widening a freeway through the center of the city.

"I'm surprised it took so long to get all that together," said Sinclair Black, cofounder of Reconnect Austin, a campaign trying to convince TxDOT to bury the highway. "We've all known what it was going to say: 'We're golden. We're going for it. Here's some dates. Get out the bulldozers."

Among TxDOT's first orders of business will be starting to expropriate property in the footprint of the highway expansion. Dozens of homes and businesses will be razed.

Contracts will go to bid early next year. Work is expected to start mid-2024.

A rendering showing 6th Street at I-35 with caps over the lowered mainlanes of the highway. The interstate itself is not visible. We just see a cross street with greenspace on either side of 6th Street. Distant buildings are nondescript white boxes in this illustration.
An illustration of what the 6th Street crossing at I-35 might look like if the highway is capped after being lowered.

TxDOT says the main feature of the project will be two lanes in each direction from Ben White to U.S. 290 East that will be reserved for vehicles with two or more passengers. The upper decks north of downtown, which opened in 1975, will be torn down.

The main lanes will be lowered for much of the distance from Oltorf Street to Airport Boulevard. TxDOT says the recessed highway could be covered with giant decks, but the city and University of Texas would have to pay for them.

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Nathan Bernier is the transportation reporter at KUT. He covers the big projects that are reshaping how we get around Austin, like the I-35 overhaul, the airport's rapid growth and the multibillion-dollar transit expansion Project Connect. He also focuses on the daily changes that affect how we walk, bike and drive around the city. Got a tip? Email him at Follow him on X @KUTnathan.
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