A busy section of the A814 Clydeside Expressway in Glasgow will close from Saturday evening for more than three weeks.
The road will be closed from the Partick Interchange to Junction 19 at Anderston, from 9pm on Saturday evening (Oct 23).
It wont reopen again until 6am on Monday 15 November.
The closure is being made to tighten up security ahead of the COP26 United Nations Climate Change Conference at the SEC, that starts 31 October and runs until 12 November 2021.
Some 140 world leaders are expected to attend the talks along with 25,000 delegates and officials.
Protests are planned to take place throughout the city over the course of the talks.
Alternative routes have been put in place but drivers are being urged to plan their journeys in advance.
Friday 5 November and Saturday 6 November are expected to be exceptionally busy, due to planned climate change related marches going from Kelvingrove Park into the city centre and Glasgow Green.
Drivers are being asked to look at travelling outside peak times and consider if the journey is necessary at that time.
Alternatively, people are encouraged to think about leaving the car, opting to travel in a different way, if possible.
Denise Hamilton is head of the council’s COP26 team.
She said: “The city is ready for what is going to be the largest gathering of world leaders that the UK has ever seen.
“But as well as world leaders, protesters and activists are also coming to Glasgow and their actions may have an additional impact and unpredictable effects on traffic in and around the city.
“That’s why we’re urging everyone to be flexible and plan ahead. We’ve put all the information we have on the 'Get Ready Glasgow' website (see link below). It is comprehensive and regularly updated.
“There are maps which show all the closures and alternative routes for roads, footpaths and cycle ways.
As well as world leaders, protesters and activists are also coming to Glasgow and their actions may have an additional impact and unpredictable effects on traffic in and around the city
“There will be congestion and disruption and some days will be far busier than others.
“But we’re using our hard-won experience and expertise to make sure that it’s as close to business-as-usual for as many people as possible.”
Nicola Blaney, head of events resilience at Transport Scotland, said, “Latest data shows the transport network in Glasgow and the Central Belt will be extremely busy during COP26.
“Severe congestion on certain days is expected due to a combination of road closures, security measures, an influx of delegates, poor weather, and likely protests.
"It's this unique mix of factors - some of which are unknown in terms of impact and timing - that makes this conference so challenging to plan for.
"However, we would urge people to plan ahead and check before they travel, as a minimum.
“By checking the Traffic Scotland and Get Ready Glasgow Twitter feeds, websites and listening to radio travel bulletins, the public can play their part in keeping disruption to a minimum during COP26."