The work will affect a 54-mile (87km) of the A12 in Essex
The A12 in Essex and Suffolk is to get £60m worth of long-waited improvements, so drivers suffer less delays.
The work will affect a 54-mile (87km) stretch from the M25 to Suffolk, covering parts of Essex.
It is one of several transport projects brought forward by the Government in a bid to boost the flagging economy.
Details of the plans, which include extra message signs at key points, were announced to the House of Commons by the Transport Secretary Geoff Hoon.
The signs and incident detection sensors embedded in the road surface will be linked to the Highways Agency's regional control centre to help provide better information for drivers, warnings of upcoming congestion and advice on alternative routes.
Mr Hoon said: "Making this funding available for the A12 reflects our commitment to support economic growth in the UK and to improve the safety and reliability of our major roads.
"The A12 is a crucial strategic link, taking traffic between the east coast ports of Felixstowe and Harwich and the wider motorway network.
"With this new package of technology in place, the Highways Agency's regional control centre would be able to identify incidents more quickly, deploy appropriate emergency service response and relay advice to road users."
Lord Hanningfield, leader of Essex County Council, welcomed the decision.
"Our efforts on behalf of motorists and businesses in Essex and East Anglia to bring the A12 to national attention are bearing fruit," he said.
"We will continue to work with the government to achieve the improvements to the A12 which will prevent the misery and congestion that is currently so often a feature of the road."