At 8am on Wednesday (2/1) a black Hyundai Coupe was travelling on the B488 Horton Road when it was involved with a collision with a pedestrian near Willow Park.
The pedestrian, a 50-year-old man, was taken to the Luton and Dunstable Hospital with serious head injuries, which are not believed to be life-threatening, where he remains.
The occupants of the car, which stopped at the scene, were uninjured.
The road was closed while officers attended and reopened shortly after 11am.
Senior investigating officer PC Ian Stevens, of the Joint Operations Unit for Roads Policing based at Milton Keynes police station, said: “I would like to speak to anyone who witnessed this collision. If you think you have information, or any dash-cam footage, which could be relevant to officers investigating, please contact police.”
Anyone with any details which could assist the investigation should contact the 24-hour Thames Valley Police enquiry centre on 101 quoting the reference 146 2/1 or you can make a report online.