The U.S. government’s road safety agency opened an investigation on Thursday about Tesla’s “Full Self-Driving” system after reports of crashes in low-visibility. The National Highway Transit Safety Administration said it will look into the Full Self-Driving’s ability to “detect and respond appropriately to reduced roadway visibility conditions, and if so, the contributing circumstances for these crashes.” Tesla reported four crashes, including one pedestrian killed in November 2023, because of sun glare, fog and airborne dust that interfered with the car’s cameras. The investigation comes at the heels of Tesla CEO Elon Musk’s announcement of a new fully autonomous robotaxi. Robotaxis without steering wheels or pedals would be available in Texas and California starting in 2026, Musk said. Tesla is also planning to implement autonomous cars with no human drivers next year. Tesla has previously said that the “Full Self-Driving” system can’t drive itself and a human driver needs to be ready to intervene at all times. The company previously recalled Full Self-Driving twice under pressure from NHTSA.