The Texas Department of Transportation is currently working through plans for expanding I-35 in Central Austin. Although it is still in design stages, the project could significantly reshape part of downtown. Here’s what you need to know.

First off, why?

As reasoning for the expansion, TxDOT officials pointed toward the highway’s issues with safety and mobility.

A recent study named a stretch of the highway the third-most-congested roadway in Texas. And with Austin’s population predicted to balloon in the coming years, experts worry this traffic will only worsen.

What do we know right now?

TxDOT is currently working on upgrading 28 miles of I-35 through Austin, stretching from Round Rock to Buda. The effort is broken into three sections: North, Central, and South. Construction has already begun on the North and South projects.

The Central upgrades would affect eight miles of the highway, between U.S. 290 in the north and Hwy. 71 to the south, and cost ~$4.9 billion. Changes include:

Two new, non-toll, high-occupancy lanes
Reconstructing east-west cross bridges
Lowering 2.5 miles of main traffic lanes from the upper deck to below ground level
Adding lanes on frontage roads, some of which would also be widened
Adding 16 new miles of bike lanes and pedestrian paths

One proposed change for I-35 involves new pedestrian walkways over the highway. | Rendering via TxDOT

What else should I know?

To put in new highway lanes, the state will need to claim land. The expansion means that ~107 business owners and residences may be displaced.

That said, the plans are not yet final. Although the design stage is expected to be completed by next year, construction may not begin until as late as 2025 and the project might not be completed until 2030.

Check out the full plans here, and submit commentary about the project online or via email before Tuesday, March 7.