If you're planning to head downtown Friday — and it's not to join the throngs of protesters demanding politicians do more to fight climate change — you might want to rethink your plans.

Thousands are expected to crowd the city centre to take part in the climate march, part of a nation-wide demonstration expected to draw a wide range of participants.

LIVE | Watch the rally on Facebook Live

One group plans to gather at the University of Ottawa's Tabaret Hall, then march over to Confederation Park, where they plan to gather at 11:30 a.m. before setting off for Parliament Hill.

A second group will muster at the corner of promenade du Portage and rue Laval in Hull, then set off at about 11:30 a.m. down rue de l'Hôtel-de-Ville, rue Laurier and over the Portage Bridge toward the Hill, where they plan to join the Ottawa group for a rally at 12:30 p.m.

(STO)

Ottawa police said to expect rolling road closures along the planned routes. The crowd is expected to start dispersing around 2 p.m., police said.

OC Transpo said in an emailed statement that staff "will be monitoring the activity closely and if delays are observed, temporary detours may be implemented."

Gatineau police also say traffic may be delayed on boulevard Alexandre Tâché east of UQO and boulevard de la Cité-des-jeunes heading toward downtown starting at 9:30 a.m.

The Société de transport de l'Outaouais (STO) said Thursday its buses will likely be affected by road closures and delays, but doesn't have specific information.

The STO is asking riders to watch its website and social media for updates.

In Kingston, there's a rally at the John Deutsch University Centre on the Queen's campus at noon followed by a march through campus.

There are more than 80 marches planned across Canada, following rallies in 150 countries last Friday.

Montreal is expecting 300,000 at its march, which will be attended by climate activist Greta Thunberg. The Swedish teenager inspired the "school strike" movement among young people to protest climate change inaction last year.