Traffic over the M2 Medway Bridge has been described by one witness as a "nightmare" after a multi-vehicle crash.
The accident happened on the coastbound carriageway between J2, A228 Sundridge Hill for Strood and and J3 for Chatham and Rochester.
Two of the four lanes were blocked during the rush-hour.
At around 6pm traffic was reported to be still moving but very slowly.
There are no details yet of any injuries.