After proposing three new concepts reimagining I-35, the Texas Department of Transportation is opening a month-long public comment forum asking Austin residents to share ideas and help shape the new highway as part of the I-35 Capital Express Central project.

TxDOT plans to reshape the eight-mile I-35 corridor between U.S. Highway 290 East and Ben White Blvd., a $6.6 billion expansion, adding two non-tolled managed lanes in either direction of the highway.

The forum is open for comment now and responses must be received by Dec. 12 to be counted.

Of the new concepts, all three propose removing the upper deck.

The first concept proposes taking the new, free HOV-managed lanes underground or in a tunnel.

(TxDOT)

The second and third concepts lower the highway below the frontage road, keeping all lanes, including the HOV-managed lanes, side-by-side.

(TxDOT)

The total cost of the project will be $7.5 billion, just above Project Connect's price tag. The project would also improve ramps, frontage roads, intersections and bike routes in the process.

TxDOT plans to meet again early next year to discuss results of community feedback. Construction is expected to begin in 2025.