A man suffered burns in a lorry fire between Pease Pottage and Handcross.
Crews are currently dealing with the fire, which happened southbound on the A23.
A spokesman for the fire service said three fire engines were in attendance.
She said: “We were called at 12.34pm to a fire involving a lorry. The lorry has been 30 per cent damaged by the fire.
“Four breathing apparatus (BA) and two hose reels are in use.
“The fire was of accidental ignition. First aid was given to one man who suffered minor burns. An ambulance was not required.”