VIDEO: San Francisco Muni Bus Catches Fire On Highway 101

SAN FRANCISCO (CBS SF) -- A San Francisco Municipal Railway bus engine overheated and caught fire Tuesday morning, briefly blocking traffic on U.S. Highway 101, according to Muni and California Highway Patrol officials.

The fire was reported shortly after 7:15 a.m. on southbound Highway 101 near the Cesar Chavez Street off-ramp, according to the CHP.

A filter in the bus engine compartment overheated and caught fire.

The bus was not in service and had no one on board besides the driver, who was not injured, Muni spokesman Paul Rose said.

The fire was quickly put out and the bus was eventually able to drive away shortly before 8 a.m. after blocking the far right southbound lane of the highway, CHP officials said.

The bus that caught fire is more than 14 years old and is among part of Muni's fleet that the agency is looking to replace with new buses, Rose said.