There is an important safety reason and an important legal reason you should never get into a car driven by someone who has been drinking alcohol to excess. It is not safe. Period. Legally, why you should not get into a car and ride away with someone who has been drinking to excess: You may not recover if this driver negligently injures you. You could place yourself in a situation in which the law does not help you.
The law in North Carolina is that if you are negligent and your negligence contributes to your injuries you may not recover from your own negligence.
If the driver of the car you are riding in was intoxicated, the insurance company will more than likely deny your claim based upon North Carolina's Doctrine of Contributory Negligence. The insurance company will say that you yourself were at least partially negligent for getting into the car with someone that you knew was drinking alcohol and that because you were negligent, you will not be entitled to recover for your injuries.
The problem in most cases is determining whether you knew or should have known that the driver had consumed enough alcohol such that the driver's mental or physical faculties are impaired.
If you can prove to the finder of fact that there was no reason for you to have known that your driver was impaired by having consumed alcohol, then you would not be at fault. However, if the finder of fact should determine that, for whatever reason, you knew or should have known that the driver was impaired by consuming alcohol, but you voluntarily got into the car with that person anyway, then you would be negligent and, under North Carolina law you would not be entitled to recover from the negligent driver or his or her insurance company.
The finder of fact may consider a number of factors in reaching a determination as to whether you, the passenger, were negligent. Among these factors are how long you had been with the driver before you got in the car, whether you knew he or she had been drinking and whether you knew how much alcohol the driver had consumed. Another important factor is the manner that the driver operated the vehicle. Was the driver weaving, stopping suddenly, going too fast or otherwise driving in an erratic manner which would tip the passenger off to the fact that the driver was impaired from having consumed alcohol.
Hundreds of thousands of cases are determined each year in North Carolina courts, primarily in traffic court, seeking to reach the issue of whether a person was too intoxicated to drive. These same issues will come into play when a determination is made as to whether you were negligent for getting into the car with a driver.
The obvious safety choice would be never to get in a car with anyone whose been drinking any alcohol whatsoever. The additional legal reason for staying out of the car is that, in all likelihood, you will not be able to recover or collect for your injuries if the negligent driver injures you.