A two car collision has meant the A1 northbound between Stamford and Grantham has been closed for much of this afternoon, Sunday July 9.
A police spokesman said: "Part of the A1 near Colsterworth is currently closed following a very serious RTC.
"The collision happened around 2.30pm on Sunday afternoon (9th July) and involves two cars.
"The northbound carriageway has been closed at the Honeypot Lane and Stamford Road junctions.
"Motorists are advised to avoid the area and find alternative routes as the road may be closed for several hours."
Accident investigation work continues this evening and traffic is very heavy in the area with queues back to the Burghley junction.
There are also delays southbound between Colsterworth and Easton.