The first issue is defining what you mean by "average." What does "average at driving" mean? If you're assigning people a competence percentage, then it's quite possible for a large portion of drivers to be above average (e.g. a thousand drivers that are 75% competent and a hundred drivers that are 25% competent). People often throw out the claim that "remember, half of everyone is below average," which implies a contiguous ordinal ranking for all people, in which case "average" is the same as "median."