RONALD LEE GILMAN, Circuit Judge. This case arises out of a traffic accident involving a vehicle driven by Angela Dortch and a Con-Way Transportation Services, Inc. tractor-trailer driven by Loren Fowler. The accident left Fowler unhurt, but Dortch suffered permanently disabling injuries that caused her to lose all memory of the collision.

Dortch alleges that Fowler’s tractor-trailer was in her lane when the accident occurred, and that Con-Way had continued to employ Fowler despite his poor driving record. She brought suit against both Fowler and Con-Way, alleging negligent causation on the part of Fowler (attributable to Con-Way under the doctrine of respondeat superior) and negligent supervision and retention on the part of Con-Way. The district court granted summary judgment in favor of Con-Way on the negligent-supervision-and-retention claim, and a jury found for Fowler (and thus Con-Way) on the underlying negligence claim regarding the cause of the accident. For the reasons set forth below, we AFFIRM the judgment of the district court.