The A27 Lewes Road, in East Sussex, is partially blocked with traffic queueing for two miles, as recovery work takes place following the incident.
Traffic is moving slowly eastbound, with delays being particularly lengthy just after the Ripe turn off, according to AA Traffic News.
Pictures show police on the scene of the crash which saw the car end up in a field.
Sussex Police have been approached for comment.
1. Delays on major East Sussex road after car crashes into field
Motorists are experiencing delays on the A27 after a car crashed into a field. Photo: Eddie Mitchell