Two drivers were injured when a lorry and van were involved in a collision on the A14 in Cambridgeshire.
The accident near Fenstanton on the westbound carriageway at about 0530 GMT caused extensive traffic problems.
The collision left the carriageway blocked and Cambridgeshire Police said lengthy tailbacks soon developed.
Diversions were put in place but officers were able to reopen one lane by 0730 GMT. Both drivers suffered minor injuries in the accident.