The collision happened Tuesday morning on Highway 180. Richard Schroeder, 63, died after investigators say he ran across the highway and into the path of a big rig.
According to investigators, the driver of the tractor trailer saw the pedestrian's concerning behavior moments before he had no choice to but to hit the brakes and hope for the best.
Dave Paris with the California Highway Patrol said, "As he was nearing that location he saw what he thought was a pedestrian in the center divider, leaping over the center divider, suddenly he darted out in front of him, in a full sprint."
Even though the big rig was empty, the 30,000 pound truck was no match for Richard Schroeder, who was killed instantly.
Accident investigators diagramed the scene for hours and looked for clues as to why the man would jump into traffic. Although the driver slowed down, his speed is estimated to be about 55 miles an hour.
The crash snarled the eastbound morning commute, making the braided ramp project an even worse traffic tie up.
Motorist George Hobbs said, "It's a rough drive down the freeway anyway with all the construction, so with something else going on, and everything bottlenecking to one lane, it's going to be a long one."
Two hours after the collision, about a mile away at the Garden Manor Board and Care Facility, workers discovered one of their residents was missing. The director says Schroeder was last seen at 2:30 in the morning smoking a cigarette with another resident.
Since the facility is not a locked one, patients are able to walk to the store or other nearby locations.
The director says Schroeder was given several psychiatric medications Monday night around 5:00 and was due for another dose when they noticed he was gone.
Investigators plan to look at all the circumstances surrounding Schroeder's death.