The A1M in West Yorkshire is closed to all traffic travelling southbound after a vehicle fire and large spillage.
A Highways Agency spokesman said: "The A1M in West Yorkshire is currently closed southbound between J41 and J40 while we assist police and emergency services with a serious collision which has resulted in a subsequent vehicle fire and large spillage.
"There is a signed diversion in place and traffic should follow the Solid Square diversion symbol.
"Exit the A1M southbound at J41 and continue onto the M62 Eastbound.
"Exit the M62 at J33 and at the roundabout take the 3rd exit onto the A1 southbound and continue to join the A1M."