Mayor Ted Wheeler says Portland police will not allow protesters of Donald Trump's presidential inauguration to block freeways or public transit lines this weekend.

"We are not going to allow people to go onto the freeways, that is for the safety of everyone," Wheeler said in a press conference this afternoon. "In addition we are going to do our level-best to prevent people from blocking our public transit."

Multiple anti-Trump protest marches are planned for this weekend, both for Inauguration Day and in the days following.

Police Chief Mike Marshman says there the city is expecting 5,000 to 8,000 people for Jan. 20 protests, and 20,000 people for the 44-block Women's March on Jan. 21.

In November, Portland saw several nights of protests, some of which turned violent when vandals smashed cars and windows of businesses. Many of those marches blocked freeways.

Police responded by deploying non-lethal crowd-clearing devices such as flash grenades and rubber bullets.

Wheeler, who became mayor on Jan. 1, says the city will not tolerate violence and vandalism.

"Peaceful protest is the bedrock of American democracy. It's something I support and our community supports and we understand a limited number of people might be under the cover of these peaceful protests to do acts of violence vandalism," Wheeler says. "I want to be clear that's something we will not tolerate."

Marshman says steps will be taken to keep the freeways open, but "it depends on the event that day," what those steps will be.

"It's just not safe," he says.

He hasn't ruled out non-lethal crowd-clearing devices, like flash-bang grendades, or even pepper spray.

"I don't want to use those, but if the crowd dynamics dictate it we might have to, unfortunately," he says.

When asked if there would be a line drawn for how much police will intervene, Marshman responded "no."