AUSTIN (KXAN) — Two sections of Interstate 35 will get new lanes. It’s a $700 million Unified Transportation Program project.

The project is part of a bigger project called the Capital Express program, which consists of three stand-alone projects — North, Central and South.

The northern segment stretches from Highway 290 East — by Koenig Lane — all the way to State Highway 45 North in Round Rock. In the northern segment of I-35, TxDOT has plans to add one lane in each direction.

The southern segment from Ben White Boulevard down to SH 45 near Buda will include two new lanes in each direction.

These lanes will be managed lanes. That means the lanes could be carpool lanes, transit-only lanes or no truck lanes, but they will not be tolled lanes. TxDOT engineers are working to figure out the best option.

However, these improvements don’t include the central section which flows through downtown Austin.

“It’s an expensive undertaking to redo I-35 through Austin and we’ve been able to get the funding for north and south and we’re still looking to figure out how we can find that central project,” said TxDOT spokesperson Diann Hodges. “But by doing north and south first, once we begin work on that central project — which is going to be disruptive, have no doubt about that — then this gives drivers an option.”

North and south improvements will begin in 2022 and construction is expected to last three to four years.

The Unified Transportation Program is a 10-year plan of transportation projects. The statewide effort listed over 8,000 projects and 74 projects in the Austin District. The full project list can be found on the Department of Transportation website.