Traffic is currently stopped on the northbound carriageway of the major route after a reported crash involving two vehicles between J21 (Witham South) and J22 (Witham North). Police are holding all traffic in the area while the incident is dealt with, leading to growing delays on the approaches. Drivers are being advised to expect significant disruption, allow extra time for their journeys and consider alternative routes around Witham until traffic is released and the A12 can safely reopen. Essex Police has been contacted for comment.