Police were called to the Dartford River Crossing towards the A2 following the incident on July 20 at around 7.35pm.
The crash involving a black Mercedes GLA and a black Honda CB600 motorbike occurred at the slip road for Princes Road.
A man on the motorbike was taken to hospital with serious injuries but has since been discharged.
The driver of the Mercedes, a 32-year-old man from London, was arrested on suspicion of failing to provide a sample for a breath or drug test, and causing serious injury through dangerous driving.
He was later bailed to return to the police station, pending further investigation.
Kent Police has issued out an appeal for anyone with dashcam footage or information to contact the force by calling 01474 366 149 quoting reference 20-1280.
