Rendering Courtesy of TxDOT
Burying downtown portion of I-35 would reunite downtown, East Austin.

Elected officials in Austin are pressing the Texas Dept. of Transportation to explore a cut-and-cap plan for a portion of Interstate 35 that adjoins the city's downtown core.

On June 20, the Austin City Council unanimously endorsed a resolution to urge TxDOT to include the plan as an option in a required National Environmental Policy Act study as an initial step toward addressing I-35 congestion.

The City Council also directed Austin's city manager to hire an economic analysis firm to study the cut-and-cap proposal and provide financing options.

Michael McGill, chief of staff to Austin Mayor Pro Tem Sheryl Cole, says putting below grade or covering the portion of I-35 from Lady Bird Lake to 15th Street or Martin Luther King Jr. Boulevard could help to "stitch back together" the downtown and East Austin areas now divided by the interstate.

"Cutting and capping [the highway] also would provide added value to the adjacent properties," says McGill. Capturing some of that value through real estate assessments or other means would help pay for capping the highway and building related improvements, he adds.

Kelli Reyna, spokeswoman for TxDOT, says adding two lanes to the six-lane road near downtown Austin is likely.

Heyden Walker, a planner at Black + Vernooy—an Austin-based design firm that has helped spearhead the cut-and-cap idea—says, so far, rough estimates suggest putting the downtown section of I-35 below grade would cost $150 million to $200 million and capping it would cost about $400 million, or about $500/sf.