The improvement works with the A10 junction at Cheshunt are due to commence in January 2021.
Other aspects of the improvement works, which have been valued from £25m-£50m include widening of the M25 Junction 25 roundabout to four lanes, widening of the M25 eastbound and westbound diverges.
Up to 6,300 vehicles per hour currently travel through the junction 25 roundabout at peak times, causing congestion and regular delays. The A10 southbound approach into the junction is also a congestion hotspot in Broxbourne.
Dave Brown, Highways Director at Graham, said: “This is another significant scheme for the South East of England and we’re delighted to have been awarded the package by Highways England under the Route to Market Regional Delivery Partnership.”