Motorists are being warned about the introduction of new speed cameras on the A120.
Some have been monitored driving at more than 120 miles per hour on the new dual carriageway between the M11 at Stansted and Braintree, Essex.
The Essex Safety Camera Partnership says it is bringing in mobile speed cameras to target dangerous drivers who threaten lives.
Two motorists have died on the 15-mile stretch since it opened in July.
Marked vans will now photograph speeding motorists from bridges over the road.