On October 17, 2024, NHTSA’s Office of Defects Investigation (ODI) opened a Preliminary Evaluation (PE24031) of Tesla’s Full Self Driving Beta and Full Self Driving (Supervised) (collectively, FSD) to assess: the ability of the FSD system to detect and respond appropriately to reduced roadway visibility conditions; whether any other FSD crashes had occurred under degraded roadway visibility conditions that are similar in nature to the four SGO-reported crashes identified in the opening document, and if so, the contributing circumstances for each of those crashes; and any updates or modifications by Tesla to the FSD system that may affect the performance of FSD in degraded roadway visibility conditions, including the timing, purpose, and capabilities of any such updates, and Tesla’s assessment of their safety impact. Tesla’s FSD is an advanced driver assistance system (ADAS) that relies exclusively on vision-based cameras and the related FSD software to detect and respond to the roadway ahead, projecting a path forward based on traffic control devices, vehicles, pedestrians, and the roadway itself. During this phase of the investigation, ODI reviewed the materials provided by Tesla detailing any actions taken, or changes, modifications, and updates made that may relate to the alleged defect. ODI reviewed information related to Tesla’s transition to a vision-only perception system, and its deployment of the strategy in vehicles. ODI’s findings include information on limitations of the vision-only perception system and updates made in response to known subject crashes. When Tesla began transitioning away from using both cameras and radars to an exclusively camera-based approach, known as Tesla Vision, in mid-2021, it developed and implemented a degradation detection system that it deployed by a software update to existing and new Tesla vehicles. On June 28, 2024, the day after Tesla submitted the SGO report of the November 28, 2023 fatal crash listed in this document,