This happened around 2 a.m. Saturday in the southbound lanes at 95th Street.
The victim, Phillip Briner lived in northwest Indiana and relatives said he was headed home from his job at the Peninsula Hotel in Chicago.
The crash left Briner's pickup truck mangled on the side of the expressway.
Saturday, loved-ones of the 21-year-old Crown Point man can't believe he's gone.
"Phillip was a great kid," said brother Michael Briner. "He was a fantastic kid."
It was 1:30 Saturday morning when Illinois State police say Briner was driving in the far left lane of the southbound Dan Ryan.
The driver of this red pickup, police say, was in the far right line when it crossed over all five lanes of the expressway and struck Briner.
The two trucks slammed into the left median wall before crossing all lanes again and hitting the right side barrier.
"I couldn't comprehend the fact that it actually happened," said friend Josiah Martin. "And I kept waiting for a phone call from him saying, 'hey, it wasn't actually me.'"
Briner was taken from the scene and pronounced dead at Christ Hospital in Oak Lawn.
The driver of the red truck was arrested and police suspect he may have been drinking.
"Anybody that is drinking and driving, I urge you to stop," Michael Briner said. "I urge them to not do it. I mean, 21 years old."
"It really bothers me knowing that this was preventable and just the fact that my best friend has just been taken away from me," Martin said.
Relatives say Briner was going to school to be a massage therapist, a young man with a healing spirit who was care-free and fun-loving.
"You want to cry, but you have to laugh because he was just hilarious," Martin said.
"When you were around Phillip, you were happy no matter what was going on," Michael Briner said. "He always found the good in things. And I think that's what he would want, really want us to do right now."
Illinois State Police have yet to file charges against the other driver, whose name has not been released. He does, however, remain in custody.