A VAN driver died after his vehicle hit a barrier on the A38.
Police thought the man fell ill at the wheel, causing him to lose control of the Transit van, which then crashed into the central reservation.
Diversions were in place for 90 minutes and rush-hour traffic faced delays of up to 30 minutes.
The incident was reported at 7.55am on Tuesday and happened between junction 28 of the M1 and the Watchorn roundabout at Alfreton.
The southbound carriageway was closed until 10.10am.
A police spokesman said: "At this stage we suspect the victim may have fallen ill at the wheel. He was declared dead at the scene and no other vehicles were involved."