All trains between Carlisle, Gretna, Annan and Carlisle have been cancelled after the vehicle went down the banking and onto the track at around 8 am.
One person has been transported to hospital in Dumfries.
A spokesperson from the Scottish Ambulance Service said: “We received a call at 07:59 am to attend an incident near Junction 22, on the M74, Gretna.
“We dispatched one ambulance and one paramedic response unit (PRU) to the scene. One patient was transported to Dumfries and Galloway Royal Infirmary.”
The incident happened near the A74 Motorway Junction 22 Gretna Interchange slip road, heading southbound, for Springfield, Gretna Green and Gretna.
An update on the National Rail website said: “An obstruction on the line between Dumfries and Carlisle means that all lines are blocked. Trains running between these stations will be cancelled. All stations between Dumfries and Carlisle will not be served. Disruption is expected until the end of the day.”
Alternative travel arrangements have been put in place by ScotRail. More information on these can be found on X @ScotRail.
