Following the alert at around 2.10pm, one fire engine from Redditch attended and firefighters in breathing apparatus then used foam to help tackle the blaze, bringing it under control by 2.40pm.
Watch Commander Stuart Crebbin from H&WFRS said: "Fortunately the driver noticed smoke coming from the engine of his car and was able to pull over to safety at the side of the road.
"While the engine compartment of his car was severely damaged as a result of the fire and there was some damage to the driver and passenger foot wells, the driver himself, the only occupant of the vehicle, was unhurt.
"Firefighters were also able to salvage the driver's personal belongings, with his wallet, rucksack, laptop computer, work records and tools all undamaged."
The road was closed for around 20 minutes while the fire, believed to have been started by a mechanical fault, was extinguished.