One person has died following a crash on the A1 northbound at Wittering.
A car collided with a lorry in a lay-by at 3.45pm.
The road is closed while emergency services work at the scene.
A police spokesman said: “This is a serious incident involving a car and a lorry.
“There will be a road closure in place.”
A spokesman for the East of England Ambulance Service said one person had been seriously injured.
Motorists are asked to avoid the area while investigations take place.
Witnesses are asked to call police on 101.