Fire was reportedly coming from the engine of the big-rig at about 5:45 a.m., the CHP said.
Crews from San Francisco fire have responded to the area to put out the fire, according to the CHP.
A Sig-alert was issued at 5:59 a.m. as the two right lanes of westbound Highway 80 have been closed, the CHP said.
It is expected that the lanes will reopen around 8 a.m., according to the CHP.
Stay with ABC7NEWS.COM for updates on this developing story.