See pic of "moped" here. It is a little scooter, 50cc I'd guess.
Fatal Semi Truck Wreck on I-95 | Breaking News | FayObserver.com
According to this story, mopeds are actually not permitted on this road.
Mo-ped rider killed in I-95 wreck :: WRAL.com
See the embedded video for what the scooter was.
Anyway, the rider is a fool - even if he spaced out and got on the I95 without thinking, you'd think he'd have woken up and moved to the shoulder.