Phase 3 construction is underway on the 183A Toll extension from Leander to Liberty Hill.

The Central Texas Regional Mobility Authority, which operates toll roads in Travis and Williamson counties, held a virtual groundbreaking ceremony April 28 for the $277 million project.

The 6.6-mile extension project adds two tolled lanes in both directions from Hero Way West in Leander to north of Hwy. 29 in Liberty Hill. A shared-use path will also be added from Hero Way in Leander to Seward Junction Loop in Liberty Hill.

The project aims to relieve projected traffic congestion due to the growth in Williamson County, according to the Mobility Authority.

"Our economy and overall quality of life relies on the ability to travel to and from our communities," Williamson County Commissioner Cynthia Long said. "So it's been an economic engine that has helped drive western Williamson County's economic development."

Road traffic on the extension is expected to open in 2025, according to the Mobility Authority.

The project is paid through mobility revenue bonds and a federal loan. The Mobility Authority received a $448.38 million loan in March from the U.S. Department of Transportation’s Build America Bureau for the project, according to the Department of Transportation. The federal loan allows for financing of the 183A Toll Phase 3 project as well as a refinancing of loans for the now-complete US 183 South and Hwy. 290 East Phase 3 projects.

183A Toll Road Phase 3

Cost: $277.3 million

Timeline: April 2021-25

Funding sources: Mobility Authority revenue bonds, U.S. Department of Transportation