Hours-of-service records, from an electronic logging device or older paper logs, are requested for an extended window before the crash, since a pattern of near-violations or scheduling pressure often explains a single day's violation. Where the vehicle was preserved, discovery includes a coordinated protocol for downloading engine control module and event data recorder information, cross-referenced against ELD, GPS, and dashcam data. A carrier's internal safety manual, driver handbook, and standard operating procedures reveal what the carrier itself considered adequate practice, and broader personnel records, including performance reviews, disciplinary records, and prior accident reports, support negligent supervision and retention theories. Discovery also reaches the carrier's broader safety history, including FMCSA compliance review results and any pattern of similar incidents.