The first extended road closure for the long-planned I-35 expansion in downtown Austin has begun. Construction started at the northbound highway bypass at Martin Luther King Jr. Boulevard, the Texas Department of Transportation announced Monday. 

The will be closed through early 2025, with traffic using the frontage road instead of the bypass.

TxDOT broke ground on the $4.5 billion I-35 Capital Express Central project in late October. Planned updates include the addition of two carpool lanes between U.S. Hwy. 290 and state Hwy. 71, lowering lanes from Airport Boulevard to Lady Bird Lake to remove upper decks, and a cap-and-stitch portion that will add above parts of the sunken roadway.

Crews have also begun to work on rebuilding and widening the Martin Luther King Jr. Boulevard bridge.

The next segment of construction is scheduled to begin early next year, near Lady Bird Lake, from Holly Street to state Hwy. 71.

Officials expect construction corridor to take roughly 10 years to complete