All emergency services are at the scene of a serious crash which has shut the A1 in both directions near Stamford.
A coach is reported to have crashed through the central reservation and the air ambulance is at the scene.
A car was also involved in the crash and one person has been airlifted to Queen’s Medical Centre in Nottingham.
One lane has now re-opened on the northbound carriageway, but there’s still approximately five miles of queuing traffic.
A second serious crash has also closed the A1 in both directions at Little Ponton this afternoon - more here
A Highways England spokesperson said: "The A1 is closed in both directions due to a serious collision between the A151 near Colsterworth and the B668 near Stretton.
"All Emergency services are en route to the scene.
"Further information, including diversion routes are to be confirmed.
"Road users are advised to allow plenty of extra journey time or to consider alternative routes, if possible."