SR 439 serves as a four-lane highway connector of I-80 and US 50. The south end of the highway is at a roundabout with US 50 west of Silver Springs, near Silver Springs Airport in Lyon County. From there, the road heads northwest into mountainous terrain, providing access to the Tahoe Reno Industrial Center and the Tesla Gigafactory. The highway continues to its end at a modified diamond interchange with I-80 located approximately east of Sparks, in Washoe County.
History
The owners of the Tahoe Reno Industrial Center constructed the 6-mile USA Parkway between I-80 and TRIC for $60 million in 2001 specifically to provide access to TRIC in Storey County. As of August 2009, it was reported that of roadway had been completed—the southernmost to the Lyon county line had only been graded and were still awaiting pavement—while roughly of the route to reach US 50 remained unconstructed.
Expansion plans
As the plans for TRIC were realized with many large companies moving in, greater plans were made for USA Parkway. As early as 2004, the road was proposed to connect with US 50 near Silver Springs, for a total distance between I-80 and US 50 of about. The connection to Silver Springs would increase regional mobility and provide air-freight shipping possibilities at nearby Silver Springs Airport. Proponents of the USA Parkway southern expansion proposed the idea of having USA Parkway accepted into Nevada's state highway system as State Route 805, but NDOT did not take such action. In 2012 and early 2013, the road network was found to fall short of TRIC's future needs. Expansion for 2017 was calculated to have a network-wide benefit–cost ratio of 9.1, and a travel reduction time of 38%, as the increased traffic could use the shorter 439 for TRIC and avoid the congestion around Reno.
Expansion project
Tesla announced plans to locate its "Gigafactory" battery production facility at TRIC in September 2014. By 2015, NDOT had officially recognized the northernmost of USA Parkway as State Route 439. Inadequate traffic management on SR439 sometimes caused traffic to back up out on the freeway, and the Wal-Mart trucks struggle to operate on time. At the end points of the future SR439, the combined traffic of I-80 and US50 was around 30,000 vehicles per day in 2015. The interchange between I-80 and SR439 had a low level of service as of 2016, causing congestion. The Regional Transportation Commission of Washoe County views the improvements as insufficient for the expected area development. To support the projected travel demand of 6,000 vehicles per day, the Nevada Department of Transportation's Board of Directors approved a design-build project to complete the southern extension of USA Parkway in an expedited manner, two years earlier than projected. The project, which involved NDOT taking over USA Parkway for $43 million and upgraded to highway standards, was planned for completion in December 2017 and was expected to cost between $65 million and $70 million. The funds to fast-track the USA Parkway build-out were obtained by deferring maintenance projects on seven low-priority northern Nevada highways. The contract price was $75.9 million. 80 workers were on site 24/6 building the road in stages, with paving started in October 2016. A two-lane roundabout was built at US 50. The I-80 ramps were also improved due to heavy traffic. At a ribbon cutting ceremony held on August 28, 2017, in anticipation of the completion of construction, Nevada Governor Brian Sandoval bestowed the honorary name of "Infinity Highway" upon USA Parkway. The extension opened for access on September 8, 2017, on budget and three months ahead of schedule.
