UDOT

Engineers monitoring cracks and displacement data 

SALT LAKE CITY, Utah (June 23, 2025) — The Utah Department of Transportation is using laser beams and drones to monitor two iconic, historic arches that span over State Route 12 in southern Utah to prevent erosion and potential damage to vehicles.

Dubbed the “Red Canyon Arches,” these landmarks were recognized in 1925 as the original entrance to Utah National Park (now Bryce Canyon National Park). Now, a century later, they still stand as a gateway to southern Utah’s natural wonders.

In phase one of the project, which started in 2019, UDOT used several sensors, drones and a stationary LiDAR tool to collect data on the SR-12 arches, located between Panguitch and Bryce Canyon. The drone captured thousands of 2D photos to turn into 3D recreations of the arches, and the LiDAR device used eye-safe laser beams to scan through and underneath the arches. Engineers then combined the data to track displacement, rockfall, deformation or any other areas of concern.  

This spring, the project secured additional funding to start phase two of the project, where crews will install additional sensors in the arches at crucial locations, as the previously installed sensors are damaged or not providing sufficient data.

“These archways are icons in our state, and we want to make sure we’re doing what we can to preserve them for the future,” UDOT Region Four Director Kirk Thornock said. “By using technology like LiDAR and these new sensors, we are able to keep a close watch on these treasured resources so that families, tourists and locals can continue to be inspired by the stunning and unique nature that exists in our state.” 

With a larger collision occurring in 2019 and other smaller scrapes happening in recent years, the arches and their shotcrete — a concrete mix sprayed onto the surface of the original rock to preserve the arches — have experienced increased damage. These incidents prompted an increased effort to monitor the arches, instead of typical biennial assessments.

“We believe good roads cost less,” UDOT Structures Project Engineer James Corney said. “That’s why we’re prioritizing extra monitoring of these arches — because preserving and maintaining our roads instead of responding reactively to larger problems costs the taxpayer less in the long run.” 

Corney also explained that the project is prioritizing placing the sensors in non-obtrusive areas so that data collection can occur with minimal impact to the area’s natural beauty.

Crews are hoping to install the new sensors in fall of 2025, after summer tourist traffic has decreased.