Police are appealing for information after a driver was nearly forced from the road.
A woman in her 40s from Braintree was driving her black Ford Escort on the A131 dual carriageway near Great Leighs when the driver of a red Ford Ka drove aggressively towards her on March 21 between 4 and 4.30pm.
Investigating officer Pc Melanie Warren said: "The Ka was being driven in a manner that left the woman absolutely terrified.
"He was shouting and swearing at the female and tried to force her off the road by swerving towards the side of her vehicle."
Anyone who witnessed the incident and can help the driver of the Ka should Pc Warren on 101 or call Crimestoppers anonymously on 0800 555111.