Overview
A fatal crash in May 2016 made the problem impossible to ignore. At the entrance to Arches National Park, vehicles attempting left turns onto US-191 were crossing at 90-degree angles against high-speed through traffic. As park visitation climbed, so did the risk.
We designed and installed a High-T traffic signal that restructured how the intersection works. Southbound through-traffic on US-191 keeps moving without stopping. Left-turning movements merge upstream, eliminating the dangerous crossing conflicts that had defined the location. A raised median removed unsafe crossing movements between northbound and southbound lanes entirely, giving drivers the gap they need to safely judge their merge. Improved striping clarified every movement.
UDOT and National Park Service officials both recognized the signal as a critical safety improvement for one of Utah’s most-visited corridors. The design didn’t just add a signal. It changed the geometry of the problem.
This work was performed by O’Neill & Company prior to its acquisition by Horner & Shifrin in 2026.
