Second phase of Sunset Road to arise on January horizon

Cars driving on Sunset Road.
In early 2023, work will begin to connect Sunset Road from I-10 to River Road.

Partners joining forces on a new 4-lane regional connection in northwest Pima County include the County, Regional Transportation Authority, Arizona Department of Transportation and City of Tucson.

Construction activities are anticipated to start in early 2023 and when fully completed, the Sunset Road corridor improvement, from River Road to Interstate 10, will provide new access to the interstate and connect with Sunset on the west side of the freeway from I-10 to Silverbell Road, a phase of the RTA project completed in 2017.

“When we can team up for a combined project, we have the opportunity to seek economies of scale to keep prices lower,” said Nancy Cole, who is overseeing the project for Pima County. “We also can plan better for alternate routes during construction to manage access and safety.”

The partnership combines the Sunset, I-10 to River Road, project with ADOT’s reconstruction of I-10 between Ruthrauff and Ina roads. The new I-10 interchange at Sunset will go over the freeway, plus the railroad tracks located just east of I-10.

“ADOT appreciates these types of partnerships where ADOT can enhance its interchange projects by using additional dollars from the RTA or region,” said Rod Lane, ADOT’s district engineer in Tucson. “This truly is a win-win approach for transportation users in the Tucson metropolitan area.”

The 2006 RTA plan provided $12.7 million in RTA funding, along with $10 million from the City and County, for Sunset Road between Silverbell and River Road. The project, which originally contemplated a new at-grade railroad crossing of the Union Pacific Railroad, is being built in two phases, with an expanded scope. The first phase, which replaced a bridge lost during the floods of 1983, was finished in early 2017. The second phase is much expanded from the original plan and includes a grade-separated crossing with the Union Pacific Railroad, a new 4-lane bridge over the Rillito River and a new signalized intersection at River Road. This expanded scope is funded in part with federal funds allocated to the PAG planning area, as well as Pima County funds and competitive federal grants. The second phase of Sunset will be built as a part of a $171 million construction contract awarded to Granite Construction Co. by ADOT for widening I-10 between the Ruthrauff and Ina interchanges.

“As projected to 2045, we anticipate growth in travel demand along this corridor, and this project will provide the needed capacity improvements,” Cole said.

PAG’s travel demand models show that approximately 16,000 to 22,000 vehicles per day are expected to use the route from Silverbell Road to I-10, and approximately 18,000 are expected from I-10 to River Road. Anticipated development in the area, particularly with Pima County’s Sunset Innovation Campus development, is expected to drive vehicle growth.

The new Sunset Road connection between River Road and I-10 is expected to greatly relieve the Orange Grove interchange and the Orange Grove and Thornydale intersection.

In addition to the previously constructed 720-foot long bridge crossing the Santa Cruz River, this project includes new bridges over the Union Pacific Railroad and Rillito Creek and provides access to The Chuck Huckelberry Loop, a regional bike and pedestrian path, from a shared-use path on the western side of the bridge.

Users of the new route will have views of the Tortolita Mountains to the northwest, the Santa Catalina Mountains to the northeast and Tucson Mountains to the west, where Tucson sunsets appropriately are sure to be a prominent feature for westbound travelers.

For now, this project is about to rise above the horizon and illuminate another economic impact corridor in the making thanks to Pima County voters who approved the project as part of the $2.1 billion RTA plan in 2006.