A series of overnight closures on the A9 got under way on Friday night.
Motorists have been urged to plan ahead and allow extra time for their journeys while the shutdown is in place.
The Luncarty to Dunkeld section will shut from 8.30pm to 6am Friday, Saturday, Sunday and Monday.
The overnight closures are required so crews can install temporary safety barriers at various locations along a 9.5km stretch, in advance of the start of works to dual the carriageway.
Transport Scotland said the barriers would allow construction work to be carried out safely next to the A9, while maintaining one lane of traffic in each direction.
Signed diversion routes will be in place on the approach to the closure area, via the A85 for northbound traffic and via the A923 Dunkeld Junction for southbound traffic.
As previously reported in The Courier, the traffic is being redirected about 48 miles and 30 miles through rural communities on either side of the A9. A 40mph limit will also remain in place until the dualling project is completed in spring 2021.
Access to the communities of Luncarty, Bankfoot and Stanley will be maintained via the local road network for the duration of the closures.
The works are weather dependent.
Gemma Montrose, project manager for Transport Scotland, said: “Road users will have already seen the gradual introduction of traffic restrictions on this stretch of the A9 from last week, including narrow lanes and a reduced speed limit of 40mph.
“The installation of the barriers is the final piece of preparatory works that will allow our contractor to begin work in earnest. We would urge road users to approach the new traffic management layouts with care, and if travel during the overnight closures is unavoidable, to follow diversions and allow extra time.”