What is the standard of care a common carrier must meet when transporting a passenger?

I am satisfied based on case law that was referred to me by counsel that a common carrier owes a passenger a very high standard of care when they get on the bus. I reference the Whalen v. Parsons & Sons Transportation Group 2005 NLCA 52, para. 30: It is not helpful to speak of shifting the onus of proof to require a common carrier to prove that it was not negligent. The ordinary principles of proof are sufficient to the task. However, given the high standard of care the common carrier must meet, the carrier may be under a heightened need to adduce evidence in response, either to prevent the drawing of adverse inferences or to negate a prima facie case, because the threshold the plaintiff must clear is lower.