A nearly two-mile stretch of Spur 399 in Collin County is preparing to open new lanes this summer as the project nears its first year of construction, TxDOT said in a June 6 update. The work will improve the State Highway 5 interchange in McKinney.
Crews are currently building new lanes and bridges and making other roadway upgrades while traffic runs on shifted lanes, according to the update. Project Manager Keton Parrish said ongoing and near-term work includes excavation and embankment operations, storm sewer installation and construction of retaining and sound walls.
“Two traffic pattern shifts are planned in the coming summer months,” Parrish said in the update, adding that the shifts to open new lanes will help enhance traffic flow, reduce congestion and support future growth in southeast McKinney. Southbound Spur 399 mainlane traffic will first shift onto newly built concrete pavement from south of Stewart Road to U.S. 75, followed by a similar shift for northbound traffic from Plateau Drive to McMakin Street.
TxDOT, city and county officials marked the start of construction with a June 2025 groundbreaking, the update said. “Collin County is growing rapidly, and TxDOT is committed to addressing the resulting highway congestion with this project,” Texas Transportation Commissioner Robert Vaughn said at the groundbreaking.
Overall completion of the Spur 399/SH 5 project is estimated for late 2029, according to TxDOT.