The incident happened at around 9.50am on, September 17, on the London-bound carriageway near the Gravesend Central junction.
A white Ford Transit Connect van was said to have collided with several other drivers before continuing onto the M25.
Officers responded to the scene and arrested a 38-year-old man from Rochester near the Dartford River Crossing.
The vehicle was seized, and the suspect has been bailed as investigations continue.
Police are now urging anyone who witnessed the incident or was affected by the collisions to come forward.
They are particularly keen to speak to the driver of a silver Transit van, which was also damaged but has not yet been traced.
Anyone with information or dashcam footage is asked to call the Kent Police appeal line on 01474 366149, quoting reference 17-0312.
