Under California Civil Code section 2100, a carrier of persons for reward, which includes a public transit agency like LACMTA, must use the utmost care and diligence for the safe carriage of its passengers and must do everything reasonably necessary for that purpose. California courts have described this as requiring a common carrier to do all that human care, vigilance, and foresight reasonably can do to avoid harm to the people it transports. This is a meaningfully higher standard than the ordinary negligence duty that applies to a typical driver on the road. The operator, and the agency operating the bus, must anticipate the vulnerabilities of standing and seated passengers, including sudden stops, sharp turns, and the time needed for passengers to safely find a seat or handhold before the bus accelerates.