U.S. 6 safety projects and Central Utah fiber work signal more delays in Thistle, Spanish Fork Canyon

Drivers through central Utah should expect continued construction impacts along U.S. 6 and nearby corridors as the Utah Department of Transportation works on multiple, overlapping infrastructure projects that stretch through 2026 and beyond.

For Sanpete County drivers, the project of greatest interest will occur at the U.S. 6 and U.S. 89 junction in Thistle. That project will reconfigure the intersection by separating traffic movements and constructing a bridge that allows U.S. 89 traffic to pass underneath U.S. 6.

The design includes longer acceleration and deceleration lanes intended to reduce conflict points where vehicles enter and exit the highway. UDOT expects the Thistle project to extend through 2027, bringing prolonged construction activity to a key gateway between Sanpete and Utah counties.

UDOT has already completed a series of safety upgrades along roughly 4 miles of U.S. 6 in Spanish Fork Canyon, including the installation of more than 9,000 feet of median barrier and six new drainage systems near Diamond Fork Road.

Crews also added crash attenuators and began installing new overhead lighting to improve nighttime visibility. The work is part of a long-term effort to reduce severe crashes along what has been described as one of the state’s most dangerous highways.

Those completed projects mark the first phase of a much larger construction timeline that will continue to affect traffic between Utah Valley and Carbon County.

A $53.4 million widening project is already underway near Sheep Creek Road, where UDOT is expanding U.S. 6 from two lanes to four, flattening curves, adding a center median barrier and improving the Sheep Creek Road intersection. During construction, drivers should expect daytime lane closures and delays of up to 15 minutes, according to UDOT.

Together, the U.S. 6 projects represent more than $110 million in programmed safety improvements between Spanish Fork and Helper, with an additional $20 million planned for pavement preservation farther east. UDOT has described the work as part of a decades-long strategy to address crash patterns and traffic growth along the corridor.

At the same time, Sanpete County drivers will encounter separate but related construction of the Central Utah Fiber project, a partnership between UDOT and CentraCom to install regional fiber-optic infrastructure along state highways.

Construction on the fiber project began in June 2025 and is scheduled to continue through the end of 2026. Work zones span State Route 28 near Nephi, Levan, and Gunnison; U.S. 50 near Salina; U.S. 89 near Sterling, Gunnison, Centerfield, and Salina; and portions of U.S. 6 near Thistle. Crews are boring and installing conduit, placing fiber-optic cable and preparing sites for future equipment installation.

UDOT lists work hours as 7 a.m. to 7 p.m., Monday through Friday, with motorists advised to watch for truck traffic entering and leaving work zones, construction equipment near shoulders, and occasional lane or shoulder closures. Increased dust, noise, and vibration can also be expected.

While the fiber project is separate from the U.S. 6 safety work, the overlap in geography (particularly near Thistle and along U.S. 6) means drivers may experience compounded delays, narrower travel lanes and reduced access at times.

UDOT officials have urged travelers to plan extra time, monitor traffic updates and remain alert through work zones as both projects advance.

With multiple years of construction still ahead, the agency has cautioned that intermittent delays are likely to remain a feature of travel through Spanish Fork Canyon and the Thistle area for at least the next couple of years.