Louis Thompson Road Tightline Project nears completion

Construction on the Louis Thompson Road Tightline Project is nearly complete. The final pavement overlay will take place in spring 2026, as November weather did not allow the several consecutive dry days needed to achieve a high-quality surface. Once paving is complete, crews will install final striping and complete roadway markings.

The new sidewalk connection down to the East Lake Sammamish Trail ramp is now open, creating a safe pedestrian link that was planned during the original trail construction. The traffic signal at the intersection has also been upgraded with new hardware, video detection, and accessible ramps with an improved pedestrian call system.

A new storm drainage system now provides detention and water-quality treatment, helping protect Zackuse Creek, Lake Sammamish, and the Kokanee salmon habitat. In total, the project includes ten new retaining walls, which made it possible to widen the roadway for a bike lane and improved shoulders—a significant investment in multimodal safety and infrastructure longevity.