Police were chasing the motorcyclist east on US Route 30 through East Caln Township just before the wreck around 1:40 a.m., troopers said.
The motorcyclist exited the highway "at a high rate of speed" onto Route 113, but lost control and hit a metal guide rail on the road's north side, said authorities.
The 31-year-old motorcyclist's name was not reported by troopers.
State police are continuing to investigate the crash.
Click here to follow Daily Voice Allentown and receive free news updates.