Police shut the M1 in both directions near junction 40 and 41 after a man fell from a bridge crossing the motorway.
Paramedics, police officers and Yorkshire Air Ambulance are the scene of the incident, with a closure currently in place between junction 41 at Carrgate and junction 40 at Ossett in Wakefield. There are queues all the way back to junction 42 at Lofthouse and police have confirmed a man has been rushed to hospital after falling from a bridge.
A spokesperson for West Yorkshire Police said: "At 2.47pm, police were called to reports of a concern for safety involving a male on the M1 southbound carriageway, Wakefield.
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"He is believed to have suffered serious injuries after falling from height. He has been taken to hospital for further treatment. Enquiries are ongoing and road closures remain in place at this time."
It is not yet known when the motorway will fully reopen. Traffic cameras show huge queues on the motorway, with the nortbound carriageway reopening just after 4.30pm.
Traffic management system Inrix says: "M1 Southbound closed, queueing traffic due to police incident between J41 A650 (Carrgate) and J40 A638 Wakefield Road ( Ossett / Wakefield). Congestion to J42 (Lofthouse). Routes through Wakefield and Tingley are heavier than normal as traffic looks to divert.
"The northbound side of the road re-opened just after 16:30, but remains heavily congested. Trapped traffic is being released past the scene on the southbound side."
