In legal terms, if someone is considered the at-fault driver in a personal injury lawsuit, you may be wondering what this exactly means. An at-fault driver is considered liable for the car accident, and is the driver who was found to be negligent. Driver negligence can range from speeding at the time of the accident, which contributed to the accident, to texting while driving. It can also include rear-ending another vehicle, driving under the influence of drugs or alcohol, and other actions (or inactions) that caused the accident to occur.