A middle-aged woman was punched in the face as she sat in traffic on Friday morning in Shenley Brook End.
The victim was driving in Walbank Grove between 8.15am and 8.30am, and was queueing in traffic to exit the area when the driver of a dark coloured saloon vehicle tried to push through the traffic.
When she told him to stop as she could not move her vehicle out of his way the offender got out of his vehicle, approached the victim, swore at her and punched her in the face.
The offender was white, in his late forties, with grey hair, and wearing jeans. His car may have been a Mercedes and the rear registration plate was missing.
There were numerous other vehicles and people in the area at the time, and anyone who saw the incident is asked to call Thames Valley Police on 101.
Alternatively call Crimestoppers, anonymously, on 0800 555 111.