The woman, aged in her 80s, was driving a Skoda Fabia which struck a barrier near Scotch Corner at around 4.50pm yesterday.
She was entering the A1(M) from junction 53 on the southbound slip road.
She collided with an Audi A5, which was travelling in the same direction, before her car left the carriageway.
The woman was taken to hospital but was sadly pronounced dead a short time later.
The road was closed to allow emergency services to deal with the incident.
Anyone who has information or dashcam footage that could help the investigation should contact North Yorkshire Police on 101, select option 2 and ask for Ed Drake. You can also email the Major Collision Investigation Team on [email protected]
Please quote incident number 12220050274.