Trooper J.L. Thorpe made the stop at N.C. Highway 42 and N.C. Highway 50, near the Wake-Johnston county line, around 10 p.m.
A couple driving by stopped and waved him over. The woman's water had broken 10 minutes earlier, and she knew the baby was on its way, Thorpe said.
Three minutes later, Thorpe said, he was holding a baby girl.
The baby was two weeks early, but she and her mother are doing fine at WakeMed, Thorpe said.