Major new roadworks have started on the M27 as part of a scheme to turn a stretch of the road into a smart motorway.
From this month drivers will face new lane closures and speed restrictions as more work gets underway.
The scheme is expected to last until about the middle of 2021, and will involve turning the route between Junction 4 (M3) and Junction 11 (Fareham) into a smart motorway.
Smart motorways are designed to ease motorway congestion by allowing cars to drive on the hard shoulder at least some of the time.
Traffic is typically monitored by cameras and ‘active’ speed signs which can vary the limit.
What work is being carried out?
The main works on the smart motorway scheme start this month.
It will include strengthening the hard shoulder, installing noise barriers, widening the carriageway into the central reserve.
Existing gantries will be removed and smart motorway technology and a new concrete barrier will be installed.
Will any lanes be closed?
Lane closures will be in place during the night when the majority of the work is taking place.
For the first part of the roadworks these will be in place between Junction 4 and Junction 8 at Whiteley.
Highways England has said three lanes will still be open during the day with a contraflow system, but these will be narrower because of the roadworks.
But the lanes will be wider than traditional narrow lanes during the roadworks, to give a greater distance between cars and HGVs in neighbouring lanes.
What about the new speed cameras?
The average speed cameras were installed along the M27, and the link road between the M27 and the M3, at the end of November.
From next week they will be switched on and will help to enforce the 50mph speed limit which will be in place because of the narrower lanes.
How will it affect my journey time?
Highways England has suggested the average journey time will increase by about 13 minutes during the roadworks.
Drivers are encouraged to take their usual daily route on the M27 but also allow extra time for their journey.
And because many people will be heading back to work next week after the Christmas holidays, it is even more important to allow extra journey time.
What if I break down?
A free recovery service will be in place 24/7 throughout the roadworks, to help any vehicles that may have broken down within the work area.
How can I make my journey easier?
Highways England has offered advice on how to help keep traffic flowing during the roadworks.
Drivers should keep to the speed limit and maintain a safe distance between them and the car in front.
People should also get into the correct lane in good time and not switch lanes.