New details revealed on Austin's plan to cover I-35 through downtown

Nearly a month after the eight-mile-long Capital Express Central project got federal approval, Austin City Council members were briefed Tuesday on TxDOT’s $4.5 billion revamp of I-36 through Austin, as well as the city-funded plan to make the most of it.

"I think we're all very interested in if this highway is moving forward, that we're doing so in a way that helps protect our community," said Austin Mayor Pro-tem Paige Ellis

The "cap-and-stitch" approach would cover lowered sections of the freeway.

"I think it’s really important for us to look at opportunities where we can utilize these spaces for low rise construction," said District 5 Council Member Ryan Alter.

What are caps and stitches? A cap is a large deck over a stretch of highway that could be covered by parks or even buildings, while a stitch is essentially a widened bridge with extra landscaping, bike and pedestrian space.

"In terms of the caps, I think they kind of speak for themselves in terms of usefulness," said District 4 Council Member Jose "Chito" Vela. "I just don't see somebody kind of reading a book on the stitch, you know, above I-35 and watching the traffic."

Under the plan, 14 caps and stitches would be paid for by the city, and one covered by the University of Texas. One cap is slated for construction next year, the rest in 2026.

The city is hoping a $105 million federal grant will help defray the cost of one of the larger decks between Cesar Chavez and 4th Streets.

"This section also includes the only portion of the caps that create a whole land bridge, so you don't have to step on the asphalt to get from downtown to the East Side," said Austin Interim Director for Transportation & Public Works Richard Mendoza.

"The financing is obviously still a pretty big question," said Ellis.

In total, the caps and stitches are estimated to cost between $600 million and $800 million. In order to build them in coordination with TxDOT, the city would have to pay the state by December of next year.

"I’m really worried that we could be in a really tight position where TXDOT ready to move forward. And, you know, we're not quite ready there," said Ellis.

"I think it'll be much better to get it all done in one shot, both from a cost perspective and from inconvenience to the public perspective," said Vela.

As for that federal grant, the city will vote Thursday, Sept. 21 on whether to apply for it.

The larger I-35 overhaul is slated to be done in 2032.