State troopers and firefighters responded to the scene, near the East Pioneer Avenue interchange, at about 1:30 a.m. after receiving reports of a semi crash and debris spilled across all eastbound lanes of the highway.
Arriving at the scene, they found a semi tractor-trailer rig on its side in the median, its load spilled.
A preliminary investigation found that the semi truck was heading west on Highway 512 when it veered off the roadway and struck the cable barrier. The semi then rolled over onto the median and dumped its load of scrap aluminum across all eastbound lanes.
The truck driver sustained minor injuries in the crash, but did not require treatment. The State Patrol says he was not impaired, and it's believed he fell asleep at the wheel.
All eastbound lanes of Highway 512 were closed for about four hours during the investigation and cleanup from the crash, although some traffic was able to get by on the shoulder. All lanes have now reopened.