The 49-week scheme on the Birmingham Road in Lichfield began on Monday and will see two new junctions built to provide access to the estate west of the road on the approach to the Falkland Road roundabout.
It is being funded by the housing developer Taylor Wimpey, which is building 450 homes at Deanslade.
The scheme will also include road widening, a new bus layby and "realigned, improved" footways.
Staffordshire County Council says throughout the works period traffic management, including temporary signals, will need to be in place so work can be carried out safely.
Towards the end of the scheme, a road closure will be put in place while resurfacing takes place. Details of these will be published closer to the time and a signed diversion put in place.
Staffordshire County Council’s cabinet member for highways and transport David Williams said: “This scheme is supporting the development of new homes to the south west of Lichfield and being funded by the developer.
"It is close to the final section of the southern bypass which we look forward to opening imminently – making a huge difference to the city and its future growth.”
“It is a lengthy works period so we would ask people to allow additional travel time if they need to use this route.
"Temporary traffic signals will be in place causing some inevitable delays so we would like to thank people for their patience while the scheme is being carried out.”
A dedicated email address S278DeansladeFarm@staffordshire.gov.uk has been set up for an enquiries about the scheme.