Drivers have been urged to take care when passing the scene of a crash on the M1 near Lofthouse.
Highways England said its teams were on the way to an collision which was blocking two lanes of the northbound carriageway between junction 41 (Carrgate) and junction 42 (Lofthouse).
It said lanes three and four were blocked and traffic as it urged drivers to only use lanes one and two when passing.
In a tweet, it said: "Traffic currently passing on both sides of the accident which makes this very dangerous. Please adhere to lane closures and use lanes one and two only."