National Highways have confirmed the plans and will hold a series of public information events, where people will be able to hear more details about the first phase of the work, which starts in September.
Simon Elliott, National Highways senior project manager, said: “This upgrade will not only deliver improvements for drivers, but there will be huge benefits for local people, equestrians and walkers alike.
"We have worked on our plans not only so that the scheme makes a real difference for the 300,000 drivers using the interchange each day, but we are undertaking a major restoration of the heathland which will have a huge positive impact on the local community and visitors to the area.
“We are holding public information events starting next Sunday in Guildford town centre so people can come and speak to the project team and find out more about our plans, and what to expect when we start work in September.”
Junction 10 on the M25 – the interchange with the A3 at Wisley – is one of the busiest in the country and experiences large queues and heavy congestion on a daily basis.
It also has one of the highest recorded collision rates across England’s motorways and major A roads nationally.
The National Highways is proposing four new slip roads for the M25 junction 10 roundabout, meaning traffic turning left can pass through the junction easily.
The M25 will increase from three to four lanes through the junction, with the A3 also becoming four lanes either side of the junction 10 roundabout.
National Highways believe the project will reduce collisions by around a third but also create a better connection and smoother traffic for the 300,000 drivers who use it every day.
The scheme also features extensive environmental by the National Highways, restoring over 25 hectares of heathland as well as planting new woodland.
The UK’s first ever heathland green bridge will link Ockham and Wisley commons for the first time since the A3 was built.
The scheme was given the go-ahead by Transport Secretary Grant Shapps last month.