TRUCKEE, Calif. — Motorists who travel on Interstate 80 should see a lot less orange this fall when a 15-year rehabilitation project comes to an end.

The “Get Across 80” campaign, launched in 1998, will wrap up by Oct. 15, having replaced 423 lane miles of I-80 between Auburn and the Nevada state line.

“We just want to thank the motorists because they were so patient, they were so understanding,” said Caltrans spokesperson Rochelle Jenkins. “We had detours and truck detours and everyone just understood the need. It was incredible.”

Prior to construction, the Sierra Nevada portions of I-80 were severely worn, with large ruts in the lanes due to high traffic volumes and the area’s severe winter conditions, according to Caltrans. Average annual snowfall on Donner Summit is 408 inches.

“We now have a smooth, safe, world-class highway that will benefit our residents, our businesses and millions of tourists who visit California,” said Caltrans Director Malcolm Dougherty.

An average of 170,000 vehicles commute I-80 over Donner daily, with that number tripling during peak times such as weekends, holidays and the ski season, according to Caltrans. In addition, $4.7 million of commerce travels over the summit every hour.

“One hundred percent of our goods — be it fuel, clothing, food, general supplies, and, yes, even lumber, which we used to export — now arrives in Truckee via Highway 80,” said Truckee Mayor Carolyn Wallace Dee, speaking at a ceremony Wednesday at the newly constructed Donner Summit Safety Roadside Rest Area.

“So you can understand that this is not just a ribbon (of highway) to those of us who live here,” she said. “It is our lifeline.”

Beyond replacing worn pavement, Caltrans and its project partners upgraded drainage systems, rebuilt the Donner Summit and Gold Run safety roadside areas and rebuilt or replaced several bridge structures, among other improvements comprising 15 projects.

“These 15 projects have brought I-80 over the Sierra Nevada back to its original glory, while upgrading the roadway to modern day standards,” said Rick Land, Caltrans chief deputy director, before more than 100 people who gathered Wednesday.

In 1960, I-80 was completed to Truckee due to the 1960 Squaw Valley Winter Olympics, with national completion in 1986, Wallace Dee explained.

Today, the highway stretches 2,900 miles from Teaneck, N.J., to San Francisco, making it the second-longest interstate highway in the U.S., behind Interstate 90 (3,101 miles).

The projects totaled $820.9 million, with funding including the use of $76.2 million of state infrastructure Proposition 1B funds.

“To those, and there are many, many, many who have worked on this project over the years, we owe you,” Wallace Dee said. “A thank you seems inadequate. You have made out lifeline whole again that will serve us well for years to come.”