The National Highway Traffic Safety Administration (NHTSA) has launched an investigation into Tesla's Full Self-Driving (FSD) technology following four crashes, including a fatal incident involving a pedestrian. The probe will examine whether Tesla's FSD system can safely operate in reduced visibility conditions such as sun glare, fog, and dust, and whether it appropriately prompts drivers to retake control in such situations. Tesla, led by CEO Elon Musk, has been pushing forward with its autonomous vehicle technology, recently unveiling a robotaxi without steering wheels or pedals. Despite these advancements, the company's FSD system has faced scrutiny and recalls due to safety concerns. The investigation encompasses approximately 2.4 million Teslas from model years 2016 to 2024 and will also look into any updates to the FSD system that may impact its performance in challenging conditions. This ongoing scrutiny has affected investor confidence, leading to a drop in Tesla's stock prices following the announcement of the robotaxi service.