Construction work to expand Sam Rayburn Tollway began in January, and crews have been working to add a fourth lane in each direction of the 26-mile tollway. The work is taking place between Lewisville and McKinney.

Currently, crews are excavating in the center median and preparing to begin asphalt paving, said Michael Rey, spokesperson for the North Texas Tollway Association. That asphalt will be the foundation for the new lanes and for the tollway’s inside shoulders.

Drivers can expect periodic single-lane closures between 9 a.m.-4 p.m. and 8 p.m.-5 a.m. until the project finishes, according to NTTA officials.

The project is expected to be completed in late 2021, Rey said.