The A43 in Northamptonshire was closed on Tuesday night after a serious accident.
Highways England tweeted at 9.15pm that the northbound carriageway between Syresham and Silverstone was shut while Northamptonshire Police dealt with the incident.
Twitter users had tweeted of severe delays in the area.
Frazer Clark said: “Massive pile-up on A43 Northampton bound between Banbury and Towcester, looks like it may be closed for some time.”
Jo Colwell said: “Traffic stationary on A43 northbound between Brackley and Towcester.”
No details were given regarding the accident. More as updates are provided by emergency services.