A serious incident that closed the southbound carriageway of the M1 in Northamptonshire involved a pedestrian and a lorry, police have confirmed.
Emergency services were called to the M1 southbound just before junction 15a at 1.30pm.
The motorway has been closed at junction 15a and a diversion is in place via the Rothersthorpe services.
Highways England has tweeted that it was a “serious incident” and traffic is already backing up to junction 16 for Daventry.
At around 4.45pm Northamptonshire Police said: “A serious collision involving a pedestrian and a lorry has occurred on the M1 Southbound near to Junction 15a.
“Cars are being diverted at the Junction 15a services and back onto the motorway.
“The road closure is likely to remain until at least 6pm.”
However Highways England has recently stated normal traffic is not expected to resume until 8.45pm and 9pm. The closure of the M1 is having a knock-on effect on roads in the south of the county with motorists on the A5 and A45 experiencing delays.
Motorists are being advised to avoid the area.