Thames Valley Police is appealing for witnesses following a fatal collision on the A5(D).
The incident happened on the northbound carriageway, one mile north of the Abbey Hill and Wolverton slip road, just after 7pm yesterday.
A blue Renault Megane collided with the central reservation. The driver, the only person in the car, who is believed to be a man in his forties, was pronounced dead at the scene.
He has not been formally identified at this time.
Anyone who witnessed this incident or who saw the vehicle prior to the collision should contact PC Ian Stevens, from the Milton Keynes Roads Policing Base, via 0845 8 505 505.
Alternatively, if you do not want to speak to police, or leave your name, please contact the Crimestoppers charity on 0800 555 111.