What is the Lone Tree Overpass project?

The City of Flagstaff will design and construct a new roadway connection to extend Lone Tree Road between Butler Avenue to the south to Route 66 to the north. The roadway will be on a bridge overpass over the BNSF Railway main line corridor and the United States Army Corps of Engineers Rio de Flag Channel; it will be grade separated. Grade separation means the roadway and railway surfaces are at different heights, which allows for flow of traffic and increased safety.

Why is this project needed?

The project will create a new north-south connection, providing an overpass over the railroad, traffic congestion relief on Milton Road, San Francisco Street, and Beaver Street, and improved multi-modal mobility to the community.

What are the benefits of this project?

The Lone Tree Overpass will:

  • Create a new north-south connection near downtown Flagstaff
  • Reduce congestion on Milton Road, San Francisco Street, and Beaver Street
  • Improve mobility to neighborhoods and businesses in the area
  • Increase safety by reducing vehicle crossing movements at railroad crossings at San Francisco Street and Beaver Street
  • Enhance regional mobility
  • Improve pedestrian and bicycle safety, mobility, and connections
  • Include aesthetic and landscape project improvements
How was this area selected for the new overpass?

The City of Flagstaff has been studying this corridor for 20 years, beginning in 2001 when the City of Flagstaff’s Regional Land Use and Transportation Plan revealed the need for an additional north-south connection near the downtown Flagstaff area.

In 2006, the Lone Tree Corridor Study developed the conceptual plans for the corridor.

In 2010, the Lone Tree Overpass Study studied several alternatives and produced a proposed alignment for the overpass. This proposed alignment will serve as the initial design concept.

In 2020, the 2010 concept was updated and costs refined in preparation of this project.

Public input has been an important part of the development of this project. The City has continually engaged the public to ensure the project will meet the needs of the surrounding community and the region.

How is this project being funded?

Revenues from Proposition 420 will fund the design and construction of the Lone Tree Overpass. Revenues from Proposition 419 will fund the design and construction of the Lone Tree Corridor portion of the project from Butler Avenue, south to Sawmill Road.

What is the project schedule?

The design phase began in early 2021. The project will be constructed in two phases: Phase One will include completion of the Lone Tree Corridor improvements and will occur from 2024 - 2026. Phase Two will include construction of the Lone Tree Overpass and will occur from 2025 - 2027.

How can I be involved and give my input?

Community input is a key element of this project. Public meetings and other opportunities for input will occur throughout the project. Connect with the project team and share your comments!

How can I stay updated on the project?

Join our email distribution list to receive project updates and to stay connected.