It happened on Christmas Eve near Thrapston.
Police are appealing for witnesses after a man in his 50's died on the westbound carriageway.
A Toyota Yaris collided with a tree and caught fire around 5.25pm near junction 13.
The road was closed for nearly eight hours.
Police crackdown on drink and drug drivers sees results
Over 800 people have been arrested for drink or drug-driving in Cambridgeshire.
The A10 at Foxton reopens after upgrade works
The road reopened on New Year's Day.
Road closed after a car was found in a ditch near Chatteris
The B1096 from Ramsey Forty Foot to Benwick was shut for recovery.
Cold weather health alert for Cambridgeshire
Freezing temperatures are forecast until Wednesday and health experts are urging people to look out for others.
Light rain
12°C
Light rain
8°C
Sunny intervals
4°C
Sunny intervals
4°C
Sunny
3°C