Where crashes happen
U.S. 36, the Diagonal, and 28th Street
Boulder County's Vision Zero program reports impaired driving as a common contributing factor in serious crashes, alongside excessive speed and centerline crossings. The U.S. 36 (Denver-Boulder Turnpike) corridor has seen multiple fatalities from head-on and single-vehicle crashes, U.S. 287 has logged numerous head-on and speed-related crashes, and Colorado 119, the Diagonal Highway between Boulder and Longmont, has seen curve-related crashes and motorcyclist fatalities. Within the city, the 28th Street and Arapahoe Avenue intersection recorded roughly 30 accidents at or near it in 2022 through early December. Boulder County recorded 22 traffic deaths in 2023, 19 in 2024, and 17 in 2025.