A semi traveling east along I-80 near Colfax barreled off the road Friday morning at 5 a.m.
The semi was slowed by a cable barrier before striking a support beam and coming to a stop in the median.
The driver, 69-year-old Lance Oatman of Idaho was pronounced dead at the scene.
The cab was split from the trailer, thousands of pounds of evaporated milk covered the road, and debris was left everywhere.
"The driver fell asleep at the wheel. There were no skid marks. That's kind of an indication," said Sergeant Scott Bright from Iowa State Patrol.
It could've been worse.
Chris Poole, a roadside safety engineer with the Iowa DOT says cable barriers aren't designed to stop semis but in many cases, they have.
"We have had lot of success capturing larger vehicles like box trucks, delivery trucks, and semis as well,” Poole told Channel 13 News.
The Iowa DOT started putting barriers up along I-35 in 2003 covering a three mile stretch near Ankeny.
Ten years later, cable barriers now line 240 miles of Iowa interstate.
They have a proven track record of saving lives.
"Where ever we have installed the cable barriers, we have no had someone crash through them and impact someone going the other direction,” said Poole.
They're also cheaper than the alternative.
The DOT estimates a concrete barrier costs eight times more per square mile.
"We can get a lot more coverage and protection in the medians with cable than we can with concrete for much less cost,” Poole said.
The DOT plans to expand, adding more cable barriers in the next two years.
Bids to install more cable barriers along i-80 in Adair County just west of Des Moines will be taken next week with construction beginning in 2014.
More barriers will be installed in Clarke County just south of Des Moines by the beginning of 2015.
Bids for that project will go out next April.