Motorists have been warned to expect disruption on the M90 as work gets under way on a £400,000 package of improvements.
The work is due to take place at the Craigend interchange, near Perth, over the coming weeks.
BEAR Scotland said efforts are being made to keep disruption to a minimum, and has arranged for some of the work to be carried out at night.
However, part of the route will be closed for three weeks, with traffic diverted along the Friarton Bridge.
The programme will see upgrades to four slip roads.
From Monday, bridge deck refurbishment will force closure of the M90 southbound slip road from Broxden roundabout for up to three weeks.
Work on other slip roads along the stretch will follow throughout this month and next.
The interchange is used by around 30,000 vehicles each day, and transport chiefs believe the improvements will considerably enhance road safety.
As well as upgrading the bridge deck, the work includes extra waterproofing, road surface improvements, installation of LED road studs and new traffic signs.
BEAR Scotland north-east representative Andy Thompson said: “These maintenance works are part of our commitment to ensure that the north-east road network continues to operate at the highest standard.
“Every effort will be made to minimise duration of the road closures to reduce disruption, and we have arranged the programme to include night-time working where possible to have less impact on motorists.”
He added: “We encourage road users to plan their journey in advance and check the Traffic Scotland website before setting out.”
After the initial three-week phase, the M90 southbound Scoonieburn slip, from the A912, will be closed overnight on October 1 and 2, from 7.30pm-6.30am.
The northbound road from the Friarton Bridge to Broxden will also be closed for two nights on October 5 and 6.
Diversions will be in the place during both closures.
Finally, the northbound route from Bridge of Earn towards Broxden Roundabout will be closed for three days from Friday October 9, at 7.30pm, and is due to open at 6.30am on Monday October 12.
Traffic will be diverted north to junction 11 at Barnhill.
The operation has been planned following talks with Police Scotland, Perth and Kinross Council and Transport Scotland.