Police said the 61-year-old man had left his own vehicle when he was struck by the lorry shortly after 13:00. He was pronounced dead at the scene.
The eastbound carriageway was closed at Junction 3 while emergency services attended, but has since reopened.
Police said they were attempting to establish the full circumstances of the incident.
A man has died after being hit by a lorry on the M8 at Livingston in West Lothian.