As of Monday afternoon, CHP was still looking for the hit and run driver with a damaged truck. They say the driver stopped for ten minutes, but then took off.
"In a scene like this, there was very light traffic, so just the impact that the body received, spread the evidence through a lot of lanes," said CHP Sgt. Sofia Mosqueda.
The impact the GMC had created a domino effect, with multiple cars hitting each other to dodge the debris.
Car and bicycle parts laid scattered on the highway near Rancho Bernardo Road, as investigators tried to piece together who the bicyclist was.
The crash was so powerful, it took them hours just to determine the victim was a man. As of Monday afternoon, his name or why he was riding on the freeway is still a mystery.
CHP says he was likely in the second closest lane to the center divider.
Bicyclists aren't allowed anywhere on this stretch of the I-15, unlike parts of the I-5 and Highway 56.
But Andy Hanshaw, the executive director of the San Diego Bike Coalition says he doesn't even believe the legal lanes on those freeways are safe for bicyclists.
"Safer, separated facilities that are comfortable to ride in and not in such high speed areas is what we're pushing for," said Hanshaw.
All lanes were reopened just before 8:30 a.m. Monday.