The A5 is closed from the Weedon crossroads in Northamptonshire all the way to the A43 roundabout at Towcester after a single vehicle crash.
It is not known when the road will re-open but police says it is expected to be closed until lunchtime and motorists are being advised to avoid the area.
Police were called to the crash at 8.35am close to Butchers Lane, Pattishall.
Abellio, who run the Greater Anglia rail line, has been named Train Operator of the Year at the annual national Rail Business Awards.
Greater Anglia train operator Abellio says it's made real steps in customer service and punctuality in its first year in charge.
Greater Anglia have apologised for the delays that have disrupted services today