Emergency services rushed to the M62 after a collision.
They were called to the eastbound carriageway of the motorway close to the M1 near Lofthouse this afternoon.
Three lanes were closed at around 3pm amid reports that two lorries had collided.
A statement by Highways England said: "There are severe delays on the M62 eastbound in West Yorkshire, due to a traffic collision closing 3 lanes between J29 (M1, Lofthouse Interchange) and J30 (A642, Wakefield).
"West Yorkshire Police are on scene, along with fire and ambulance services, and our Highways England Traffic Officers. This has resulted in severe delays on the M62 approach back towards J27 (M621, A650, Gildersome).
Road users are advised to allow extra time for their journeys, and consider alternative routes where possible.
West Yorkshire Police spokesperson said it is believed that a collision occurred, possibly between two vehicles, but that nobody is thought to be hurt.
However the force's roads policing unit described it as a "serious collision" on Twitter.
Bus company Arriva Yorkshire said the disruption could mean delays on its 187, 188, 189 services.