Interstate 15 passes through extremely rugged terrain, making it difficult to widen the highway or change its footprint.
Though many Arizonans don’t travel the 29-mi. stretch of Interstate 15 in northwestern Arizona, they see high traffic volume due to its use by commercial trucks.
To ensure this section of Interstate 15 continues to provide a safe route for the approximate 24,000 vehicles that travel it daily, linking cities such as Los Angeles, Las Vegas and Salt Lake City, it is being reconstructed in segments, as funding will allow.
Work began in July by prime contractor FNF Construction, of Tempe, Ariz., with the removal of a layer of the existing pavement.
Interstate 15 passes through extremely rugged terrain, making it difficult to widen the highway or change its footprint. However, a feasibility study is underway to evaluate possible shoulder improvements, rock fall containment enhancements and adding new climbing lanes on the entire I-15 corridor in Arizona, said Dustin Krugel, public information officer, of the Arizona Department of Transportation.
The Arizona State Transportation Board awarded an $11.6 million contract to fund this segment, which is the first of two projects to repave the entire 29 mi. (46.7 km) of Interstate 15 in Arizona.
The ADOT has invested more than $15 million over the last decade to keep this corridor up to standards, Krugel said. ADOT also has budgeted nearly $15 million to repave another 13-mi. (21 km) portion of I-15 that extends to the Nevada state line in 2015.
In an effort to shorten the construction schedule and impact on motorists, FNF Construction worked 16 hours a days, seven days a week, completing work during off-peak hours, including at night, when there were fewer drivers on the road.
“Any construction project in this very remote stretch of four-lane roadway will impact traffic due to the lack of alternate routes,” Krugel said.
“Typically a project of this magnitude, 16 miles long in a very remote area, would take much longer to complete.”
About 478,000 sq. yd. (399,669 sq m) of the existing layer of bituminous pavement was removed on a 16-mi. (25.7) stretch starting at mi. marker 13 and continuing to mile marker 29, from the Virgin River Gorge to the Utah State line.
Crews placed 129,000 tons (117,027 t) of asphalt concrete mix for the first layer of pavement in the pavement preservation project and will add 14,000 tons (12,700 t) of asphalt concrete friction course as the top layer of pavement in the spring.
“Milling, paving and grader machines were used for this pavement preservation project,” said Krugel.
Currently, the 16-mi. (25.7 km) paving project is shut down for the winter in this desert region where temperatures dip to around 30 F overnight during December and January. Work will resume in the spring to apply the top layer of asphalt to the roadway, which is expected to take about one month to complete.
“ADOT shut down the project for the winter because we want to make sure the project is done right and ensure that this new layer of pavement will last a long time and be a great benefit to drivers for many years to come,” Krugel said. Permanent roadway markings also will be added in the spring.
At this time ADOT will begin another $4 million project on I-15, which includes reconstructing and upgrading the existing Desert Springs interchange at mi. marker 9, including the addition of a new underpass.
Eight bridges in seven locations also will be included in future construction on Interstate 15 in Arizona, bringing the total cost of the project to about $320 million, according to Krugel.
ADOT is currently conducting a feasibility study to rehabilitate all eight of the I-15 Virgin River bridges, which were constructed in the late 1960s and early 1970s.
“While the bridges are still considered safe for travel, they require extensive refurbishment to continue supporting traffic,” Krugel added.
“More than 1.4 million commercial trucks travel annually on Arizona’s portion of this Interstate.”
The ADOT, along with the Nevada DOT and the Utah DOT applied for a Transportation Investment Generating Economic Recovery (TIGER IV) grant to rehabilitate bridge 6 at mi. marker 16. Word was recently received that a $21.6 million TIGER grant was received from the Federal Highway Administration to rehabilitate this bridge in 2012.
According to the U.S. DOT, TIGER grants are awarded to transportation projects that have a significant national or regional impact.
Projects are chosen for their ability to contribute to the long-term economic competitiveness of the nation, improve the condition of existing transportation facilities and systems, increase energy efficiency and reduce greenhouse gas emissions, improve the safety of U.S. transportation facilities, and enhance the quality of living and working environments of communities through increased transportation choices and connections.
Reconstruction of bridge 6 is expected to begin in 2013 and be completed by 2015, Krugel said. The total project cost to restore bridge 6 is $27 million.
Proposed improvements for the bridge include removing and replacing the existing bridge deck, girders and median/exterior barriers, widening the new bridge deck to provide shoulders that meet current standards, widening the roadways approaching the bridge to match the new bridge width and reconstructing and strengthening piers and foundations.