A COLLISION is causing heavy rush hour traffic along a main road.

The A12 Colchester-bound is partially blocked between Junction 17 Howe Green/A130 and Junction 18 for Sandon/Danbury.

There are reports of a collision in lane two, with police in attendance.

Queues are currently back for five miles to Junction 16 at Galleywood.

There is also slow passing at the scene on the London-bound side.