Eduardo Rivas, 33, of Cameron, NC, was with his wife and two young children in a Volkswagen SUV.
Cary officials said they think the car hydroplaned and he got out. That's when a second car they think hydroplaned and hit him.
The driver of the second vehicle was taken to the hospital as a precaution but didn't appear injured.
About the same time, traffic on Interstate 40 eastbound also slowed to a crawl after a crash near US 70 Business. There were several vehicles involved, but no serious injuries reported.
The highway reopened just after 7 a.m.