KFMB-TV video shows the firefighter being put in restraints and led away by a California Highway Patrol officer.
He was held briefly in a patrol car but not arrested.
The unnamed firefighter, donning full gear, can be heard talking to news crews as he is being handcuffed.
U-T San Diego said crews were helping victims after a car overturned on Tuesday night on Interstate 805.
One person was taken to hospital.
Chula Vista Fire Chief Dave Hanneman said a fire engine was parked behind an ambulance for safety reasons when a CHP officer demanded it be moved out of traffic lanes.
The firefighter said he would check with his captain but was told to move it immediately or face arrest.
CHP spokesman Jake Sanchez did not comment on the arrest immediately.
Officials from the fire department and CHP have met to discuss the incident.Post published in: World News