Hoyal said investigators aren't sure why Madison was along the shoulder whether he was trying to cross the street or was jogging.
Madison hit the van's windshield before tumbling onto the road. He was taken to Intermountain Medical Center in Murray where he died early Thursday afternoon, Hoyal said.
The 20-year-old male driver of the van stopped to offer assistance.
No citations were immediately issued. The cause of the accident was being investigated, but Hoyal said lighting conditions the sun was rising were being considered, along with any possible driving distractions.
Madison had spent 40 years as a programmer at MediaOne, which oversees printing and advertising for The Salt Lake Tribune. Though he left them sooner than expected, his peers said Madison left the company better off than he found it.
"He brought us from the Stone Age to where we are now. Newspapers are shrinking, but they're shrinking with top-notch systems [thanks to him]," said Jerry Jennings, who hired Madison and worked with him for 39 years. He was also a man of principle, Jennings added. "A lot of people can be compromised for money or position, and he's one man that could not."
Madison was a pioneer at MediaOne who advocated for improved technology, said Kim Muggleston, vice president of IT. In the 40 years Muggleston worked with Madison, he knew him to be a reserved man who always kept his cool. Even when Muggleston was stressing over a project, Madison kept a level head and saw it to the end.
On top of that, "Larry was probably one of the nicest guys you'd ever want to meet," Muggleston said, who sometimes struggled to speak about his colleague. "We're going to be lost in the department without his guidance and his knowledge. It's a tragedy for his family and everyone who knew him."