Around 1:45 p.m, Contra Costa CHP and Walnut Creek police responded to a man standing in the center divide of eastbound Highway 24 and northbound Interstate 680.
Upon making contact, police say the man appeared to be suffering from a mental health crisis.
A negotiating team was called to the scene, and officials shut down the freeway, causing major delays.
WATCH: SKY7 captures Wednesday's traffic nightmare on East Bay freeways
Amanda Youkhaneh was one of the drivers caught in slowdown.
"I sat at a complete stop on the freeway. It was just bumper to bumper. I went on just Google Maps to see my ETA just shifting," she said.
She says she had no idea what was causing the massive backup.
"I figured there was some massive accident I was coming up on or something," Youkhaneh said.
It was a similar story for Chase Hoover-Mohun too.
He says he was trying to drive from Berkeley to Pleasant Hill.
VIDEO: Person taken into custody after police activity snarls Hwy 24
A drive that normally takes him around 35 to 40 minutes, but Wednesday around an hour and 45 minutes instead.
"No one was having fun in there. People were looking at each other, shrugging," he said.
Walnut Creek police say the man ultimately turned himself over to officers peacefully around 5:30 p.m. He's now receiving medical care.
But even after the incident ended, some drivers tell ABC7 News the day's events were still being felt.
Yakinn Bello says he was running hours late to pick up his kids.
"They are still waiting for me to pick them up," he said.
While others say they planned ahead and weren't impacted as much.
"I plan ahead. I'm very conservative because you never know what can happen. So it was okay," said driver, Megginn Yuen.
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