Drivers are being warned to expect delays as part of the A9 dualling project is finished off later this month.
Road users were given full access to the 9.5 km of new dual carriageway – which cost £96 million – between Luncarty, north of Perth, and the Pass of Birnam on August 30.
It provides 15km of continuous dual carriageway from the Inveralmond Roundabout to Birnam for the first time.
The northbound carriageway will be reduced to a single lane for five nights, north of Gelly Wood, from Saturday September 25.
‘Allow additional time for journeys’
The lane closures will be in place from 9pm to 6am each day to allow BT to lay cables.
A Transport Scotland spokeswoman said: “Please allow additional time for your journey and take care on approach to the works area.
“Traffic management is weather dependent and subject to change, therefore please refer to the Traffic Scotland website for updates.”
Work to dual the 9.5km of single-carriageway north of Perth began in February 2019 following the appointment of Balfour Beatty as the main contractor in September 2018.
The project involved the construction of four new bridges over the A9 and the removal of all direct access roads to the carriageway.
Transport Scotland says the measures have improved safety and “reduced driver frustration and stress” by providing more opportunities to overtake safely.
It has also created about 4km of new and upgraded pedestrian, equestrian and cycle routes.
Campaigners hoping A9 and A96 upgrades will be abandoned under SNP-Green pact