When a section of highway began to sink as the soil weakened beneath it, the Nevada Department of Transportation had to inject an underground stabilizing agent before it could repair the road surface.

The agency recently completed repairs to U.S. 50 in Dayton, smoothing and repaving lanes in both directions on a route traveled by about 19,000 vehicles each day.

The roadway depression developed over recent months, creating “dips in the driving surface” on a section directly east of Dayton Valley Road, NDOT said.

It closed one eastbound lane in mid-April, and reportedly used ground-penetrating radar and borings to assess the roadbed conditions.

In early May, an NDOT contractor “injected 10,000 lbs. of specialized polyurethane solution, which automatically expanded underneath the roadway, lifting the depression approximately 6 in. and reinforcing and stabilizing the soil underneath,” according to the agency.

It also said that work cost about $160,000 and took nearly a week, but allowed NDOT to avoid having to fully excavate, refill and repave that highway section — a process that would have required more construction time, cost and related traffic delays.

Following those initial repairs, the agency reopened the previously closed lane to traffic, as it waited for warmer temperatures in mid-June to make the final surface repairs.