Work to upgrade the Lostock Lane/Stanifield Lane roundabout in Lostock Hall are due to begin on January 5.
The improvements, which are being carried out by Lancashire County Council, will see the roundabout widened to create extra lanes. New traffic lights will also be installed.
This work will improve capacity at the junction, reduce congestion and make traffic flow more smoothly.
New cycle lanes and shared footways and cycleways with controlled crossings will also make it much safer for drivers, cyclists and pedestrians.
The improvements and other work to upgrade the A582 form part of City Deal, a 10-year project for Preston, South Ribble and Lancashire worth £434m.
City Deal will deliver major road and transport infrastructure improvements and create more than 20,000 jobs.
Phil Wilson, Lancashire County Council’s highways project manager overseeing the scheme, said: “This is a very busy roundabout, particularly during rush-hour.
“The improvements will reduce journey times and make it much safer for drivers, pedestrians and cyclists.
“By providing better footways and cycleways, the improvements will also encourage more environmentally-friendly ways of getting around the area. As with all improvement work of this nature, some disruption is unavoidable, but we will do our best to keep this to a minimum.”
Signs informing people about the improvements have now been placed on the approaches to the roundabout.
The work is part of a scheme to upgrade the A582, one of the main routes through South Ribble and in and out of Preston, by reducing congestion and ensuring it can handle higher volumes of traffic.
The improvements follow the opening of the new junction of the A582 at Chain House Lane last month.