Road and Highway Builders Extends I-580 to Carson City
You could look at a particular piece of 60-inch reinforced concrete pipe as just another unremarkable section for the drainage system on a large road building project.
But contractor Road and Highway Builders, of Reno, Nevada, working on the I-580 Carson City Freeway Extension, saw that pipe as an opportunity to save a lot of time and trouble.
The issue was removal of almost 1 million cubic yards of earth. The excavation was necessary to lower the elevation of sections of the freeway, reducing traffic noise, and to bring the road below existing overpasses.
An Innovative Earthmoving System
Getting all that material off site would usually call for loading about 200 trucks a day for over six months, with all the associated traffic management issues. Project Manager Will Hellickson explains: "We were able to install a 36-inch conveyor that passed 140 feet under South Carson Street and from there an a overland conveyor belt about 1,600 feet long took them up Spooner Summit to the dump site."
Hellickson said it was a first for the contractor. "We use a lot of conveyors in our crushing and plant operations but this is the first time I've ever used it in an application quite like this."
Hellickson estimates about 600,000 cubic yards of material were removed by the conveyors, rather than being loaded on trucks. Nevada Department of Transportation (NDOT) officials were pleased with the results of the innovation.
Overall, the $42 million project is well on its way to scheduled completion next year. Beginning in June 2015, the aim of the job is to pave and open the last approximately 4 miles of the Carson City Freeway to traffic between Fairview Drive and the Spooner/U.S. 50 junction in south Carson City. Funding has come from federal transportation funds, the state highway fund and Carson City.
The freeway is aimed at increasing traffic mobility and safety with an interstate bypass to help remove through-traffic congestion from downtown Carson City. NDOT estimates that by 2035 the freeway section will see usage by 43,000 vehicles daily. The freeway has two lanes in each direction and is designed with provisions for future widening in the median.
The current project is the last phase of a long term effort. Meg Ragonese, Nevada Department of Transportation Public Information Officer, said, "Throughout the past decade, the Nevada Department of Transportation has phased construction of a new freeway extension through Carson City. Previously, Nevada was one of a handful of states which did not have an interstate connecting into the capital city. The new freeway not only connects Interstate 580 from Reno into the state's capital, but provides enhanced traffic mobility across Carson City and the region."
Previous phases had improved and re-aligned U.S. 395 north of Carson City, built a grade-separated crossing at Snyder Avenue over the future freeway, made drainage channels, relocated utilities and prepared grading for the southern leg of the project.
Erecting Sound Walls
Paving of the future freeway began in late August, when crews began pouring hot mix asphalt (HMA). "We're about 60 percent through with the dense grade paving," said Hellickson. "Currently we're paving, we're erecting sound walls."
He noted that Road Highway Builders decided to use precast panels for the 2.7 miles of sound walls to be installed in the residential area.
"We came up with a plan to precast 14,000 feet of sound walls in Las Vegas instead of casting them in place here in northern Nevada," said Hellickson. "So we did that and hauled them up here and erected them on site. We're about 80 percent through with the erection of that work."
Hellickson said the contractor, which has an average of about 70 workers in the field each day, is now also running slip form machines to construct the concrete barrier rail. Next up will be re-construction of the intersection of the new freeway and South Carson Street. NDOT officials note that the future four-way intersection will be controlled by a traffic signal coordinated with surrounding signals for optimum traffic flow.
Remaining items on the to-do list include: a 4,500 foot long two-lane on-ramp will be constructed to connect northbound U.S. 395 to the new freeway; lanes and ramps connecting the Carson City Freeway to southbound U.S. 395, U.S. 50 and northbound Carson Street.
"With paving underway, the future freeway is really taking shape," NDOT Resident Engineer Ashley Hurlbut commented. "The project is on schedule, and we're well on our way to completing an interstate that will further connect Carson City and the entire region."
Then NDOT's mission will be completed. One possible future improvement would be replacement of the signalized intersection with an interchange. "No funding has been identified for that," said Ragonese. If funding did become available, NDOT foresees that work happening in the mid to late 2020s.