The police have confirmed that the HGV driver who was killed in the incident is a 38-year-old man from the Stockton-on-Tees area. His next of kin have been informed but the police are not expected to be in a position to name him until tomorrow at the earliest.
The 58-year-old driver of the HGV with a curtain side trailer, from the North Lincolnshire area, is being treated at Darlington Memorial Hospital. His condition is described as critical but stable.
No-one else was injured.
The latest indication is that the collision scene on the northbound carriage of the A1 will remain closed until about 6pm. A diversion has been in place throughout the day.
The southbound carriageway is open.
Anyone with information that could assist the collision investigation is urged to contact North Yorkshire Police on 101, select option 2, and ask for Martin Usher.