The motorcycle, a tractor-trailer, and a Honda Pilot were involved in a wreck near Exit 58 around 11:45 a.m., according to state police.
The Lehigh County Coroner's Office said the motorcyclist was pronounced dead at the scene. Authorities said he was a Coppersburg resident but did not report his name Wednesday.
The 59-year-old tractor-trailer driver and the 42-year-old in the Honda were not injured, troopers added.
I-78 was closed until about 3:30 p.m. while crews worked the scene.
State police and the District Attorney's Office are investigating, according to Coroner Daniel A. Buglio.
Click here to follow Daily Voice Slate Belt and receive free news updates.