This is an archived article that was published on in 2014, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Travel between St. George and Las Vegas is about to slow significantly — and probably for more than a year — because construction on Arizona's 29-mile stretch of Interstate 15 will reduce it to one lane in each direction in several spots.

On Monday, Arizona is scheduled to begin a $2.8 million project to upgrade the surface of three southbound bridges in the Virgin River Gorge. Work is expected to be completed by next summer.

But the Arizona State Transportation Board also is expected to award another $27 million project later this month to reconstruct a bridge at milepost 16; the project would replace the bridge's girders, deck and rails and widen the roadway through the narrow gorge. It is expected to begin in spring and be completed in 2015.

The Arizona Department of Transportation said in a news release that I-15 will be narrowed to one lane in each direction at the sites of the bridge projects, so delays are expected. The majority of work will occur in southbound lanes; consequently, the northbound lanes will accommodate two-way traffic.

Construction will occur primarily on weekdays from 6 a.m to 6 p.m.

In 2012, ADOT completed an $11.6 million pavement improvement project from the Virgin River to the Utah state line, and has budgeted about $15 million to complete repaving the rest of the Arizona segment in 2015.

Eventually all eight bridges in Arizona's section of I-15 will need to be rehabilitated, the agency said in a news release. It said it is committed to providing needed upgrades on the stretch, but covering the estimated $250 million total pricetag could be a challenge.

Arizona in 2011 had proposed charging a toll of $1 to $3 for cars and $6 to $10 for trucks to travel on the section of I-15 between St. George and Mesquite, Nev.

Utah Gov. Gary Herbert protested loudly to federal officials then that Arizona was trying unfairly to shift the cost of fixing bridges to Utah and Nevada drivers. The Utah Trucking Association compared Arizona to the troll in the Billy Goats Gruff story who threatens to eat anyone using his bridge.

When Arizona's segment of I-15 opened in 1973, the Virgin River Gorge roadway was then the most expensive section of rural highway, per mile, constructed in the nation.

Despite its remote location, the stretch is one of the most heavily traveled corridors linking southern California and the Rocky Mountain region. More than 1.4 million commercial trucks use it annually.

More information about the projects is available online at"> Travelers outside of Arizona seeking to check road conditions may call 1-888-411-ROAD, or may dial 511 while in Arizona.