Emergency workers checked out drivers and passengers while tow trucks took cars away.
Chopper 11 HD was over I-40 near Miami Boulevard and Davis Drive where the major pileup took place.
At least 50 vehicles were involved in two separate incidents along the westbound lanes.
Investigators said they are trying to figure out what happened, but they have not filed any charges. At this time, it is not clear if any are pending.
Initial reports stated it was raining and a tractor trailer may have side-swiped a number of vehicles which careened into other cars.
From Chopper 11 HD there appeared to be several different accident sites, while drivers said it was a chain reaction.
"All I could do was brace myself and then a succession of cars hit from behind and in the front," driver Terrence Patterson said.
"When I looked in my rear view mirror all I saw was windshield coming at me real quick and I just closed my eyes and said, 'oh God,' and it hit me and drove me into some other vehicles," driver John Hughes said. "I think the rain was probably the biggest cause. A lot of people were not able to see it was a hard rain, a misty. Their vision was impaired."
The victims involved in the accident said they were asked by Highway Patrol troopers to meet at a hotel just off the next exit to give statements and exchange information with other drivers.
Drivers said they fear the incident could be an insurance nightmare.
Commuters trying to avoid I-40 said back-ups clogged a lot of other major travel arteries across the Triangle.
Interstate 40 west was shut down for several hours. Backups were reported all the way to Cary around Harrison Avenue.
Authorities reopened one lane around 6 p.m., while other lanes were reopened hours later.