"The way the pipe came through the vehicle; most likely it came bouncing off of a vehicle," CHP Ofc. Tyler Hahn said.
The Volvo veered left into the center divider, went up an embankment and came to rest. The CHP arrived to find the driver deceased inside the vehicle and the engine still running, Hahn said.
ABC7 News has learned the victim is 33-year-old Michael Potts of Lodi. His brother told ABC7 the Placer County resident was on his way into the Bay Area for a weekly meeting. Potts leaves behind a wife and three children.
"Sometimes stuff falls off; you got to be very careful about securing everything," one big-rig driver told ABC7.
Investigators believe the metal pipe is likely one commonly used as a leveraging tool to tie down materials on flatbed trucks.
Hahn called the case "completely a freak accident" and said it "literally is being in the wrong place at the wrong time."
It took investigators hours to clear the scene; the traffic back-up stretched for miles.
Investigators tell ABC7 News they do not believe the driver even knows the pipe may have bounced from their compartment or tray. They're hoping that other commuters moving through the area at that time can provide clues and aid in the investigation.
Anyone with information on the case is asked to call the CHP at (925) 828-0466 and ask for Hahn or Officer Azevedo.
Bay City News contributed to this report.