The A127 is blocked near Basildon due to a three-vehicle crash and police and paramedics are both on the scene.
Traffic is stationary between Gardiners Lane South, near the Mayflower Retail Park and the junction with the A176 Upper Mayne for Billericay and Noak Bridge.
The accident happened shortly after 5pm westbound on the Southend Arterial Road.
PC Mike Bignell of Essex Roads Policing has tweeted that police and ambulance are dealing with the incident and that one lane is open, although other reports suggest the whole road is closed.
Another Twitter user Antony Baker tweeted: “A127 London bound is at an absolute standstill, anyone know why?”
A127 congestion due to two vehicle collision from Wickford towards Laindon. Police and ambulance dealing 1 lane open
— PC Mike Bignell (@PCMikeBignell) November 12, 2016