
The carriageway was closed in both directions between the junctions with the A428 and the A6, causing long queues to build up in the area with delays of roughly 30 minutes added on to typical journey times.
The closure also led to heavy traffic causing jams on Woburn Road, Elstow Road, and on the B531 through Kemptson.
The road has since re-opened.
A Bedfordshire Police spokesman said: "A road closure was in place while officers attended reports for the concern for the welfare of a person."