Southern Nevada's busiest thoroughfare, Interstate 15, sees more than 200,000 vehicles a day and is plagued by gridlock and accidents.

Photo courtesy of Las Vegas Paving Corp.
The project includes a total of 26 bridge segments to help alleviate traffic snarls and improve safety.

Design-build contractor Las Vegas Paving Corp. began work in late 2009 on a solution: a $246.5-million widening of I-15 South between Silverado Ranch Boulevard and Tropicana Avenue. Jacobs Engineering Group Inc., Pasadena, Calif., performed design.

The project is being underwritten by the Las Vegas Convention Visitors Authority, the public-private entity charged with bringing more visitors to town through hotel room tax-backed bonds. “Southern California represents about 25% of all our business, so we have to make sure they can get here,” LVCVA President Rossi Ralenkotter says. “Transportation is the key to bringing business to Las Vegas.”

The project will upgrade seven miles with a new asphalt and concrete roadway and add three new bridges and reconfigure three interchanges. Other improvements include 35 retaining walls, storm drainage and 1.5 miles of sound walls, as well as landscaping and an intelligent messaging system.

As big as the job is, it has grown larger since breaking ground. The Nevada Dept. of Transportation added express lanes between the 215 interchange and Silverado Ranch Boulevard, ramp meters and other upgrades. Project costs grew by $6 million as a result.

Las Vegas Paving is taking a divide-and-conquer construction approach by splitting the job into four major zones, with work taking place as plans are still being drawn. The contractor is performing 75% of the work itself, which, the company says, gives it better control over schedule, quality and safety.

The contractor was able to build upon the success of Nevada's first design-build project in January 2010—a $242-million widening of I-15 North, completed under budget and nine months early. “That project was a great learning process,” says Corey Newcome, Las Vegas Paving division manager. “I doubt we would be doing this job if we hadn't done that other one.”

The current undertaking requires up to 300 craftspeople, 95 designers and 3,500 pages of plan documents. The contract carries up to $500,000 in bonuses for early completion and $10,000 a day in potential late penalties, Newcome says.

Completion is scheduled for mid-2012, although components are being opened as they are finished. The $22.6-million Sunset Road Bridge made its debut on Jan. 13. The 550-ft-long by 60-ft-wide, four-span steel girder bridge has four travel and two turning lanes, with 29,500 sq ft of precast abutment walls.

The trio of interchanges will soon have added capacity, too, thanks to a combination of wider roads and new collector-distribution lanes that eliminate merge and weave traffic. Blue Diamond Road gets a new 900-ft-long direct connection flyover from eastbound Blue Diamond to northbound I-15, while the 215 Beltway interchange is undergoing median and bridge widening and getting a new ramp from 215 westbound to new collector-distributor roads.

“The widening will add 30% to 85% more capacity to the project corridor, depending on the segment,” says Steve Hagel, Jacobs' deputy program manager. “Braiding of the successive on and off ramps will eliminate the severe weaving problems, which in turn will have a significant positive impact on traffic flow and safety.”