The National Highway Traffic Safety Administration reported that 3,871 vehicles are affected by the software defect. Investigators found that the autonomous systems frequently prioritized avoiding other traffic hazards while failing to recognize construction signage, leading the vehicles to drive at speed through closed freeway lanes. In one instance this May, seven Waymo cars navigated between traffic cones to enter an active construction site in the San Francisco Bay Area.

Waymo’s internal safety committee began investigating after a string of incidents in Phoenix last April. The company has since implemented temporary freeway driving restrictions while it develops permanent software patches. These updates are intended to improve the system's detection capabilities and adjust operational protocols to ensure cars correctly identify and avoid restricted zones. This regulatory action arrives as competitors, including Uber, Lucid, and Mobileye, push forward with their own autonomous service expansions across major U.S. cities.