Demonstrators now face up to two years' jail and fines up to $22,000 under the Roads and Crimes Legislation Amendment Act, which the governor signed overnight after it was passed by parliament.

Police said they arrested and charged five people at Lilyfield in Sydney's inner west on Wednesday for disrupting traffic, confirming the arrests were made under the new legislation.

The group - two women, aged 61 and 48, and three men aged 36, 46 and 77 - were taken to Newtown Police Station where they were charged with disrupting vehicles. They will face court later today.

The activists, who are affiliated with environmental advocacy group Fireproof Australia, sat on the road at the entrance of the A4 City West Link Road on Wednesday.

The climate action group said one of the protesters was Martin Wolterding, a biology and marine ecology professor from the Blue Mountains.

Fireproof Australia later released a photo of police arresting the activist.

"Since 2018 we have experienced droughts, fires, floods and a pandemic. The time to act is now," Wolterding said.

The latest arrests come a day after four Fireproof Australia activists were detained on Tuesday for blocking traffic on General Holmes Drive near Sydney Airport.

The group said the demonstrators were released late on Tuesday and hit with fines ranging from $150 to $400.

They were charged with wilfully preventing free passage of a person or vehicle, refusing to comply with police directions, and refusing to disclose their identities.

The group's demands include immediately re-housing flood and bushfire survivors, implementing recommendations of the royal commission into the Black Summer bushfires, and to "smoke-proof" schools, aged care and disability facilities.

Premier Dominic Perrottet said on Tuesday his government would continue to "throw the book" at protesters who disrupted the lives of commuters.

He said the government respected and promoted free speech but people must exercise their right to protest responsibly.

Mr Perrottet warned activists they risked alienating the public and losing support for their cause.

Metropolitan Roads Minister Natalie Ward described the climate action protests of recent weeks as selfish.

"It was essential ... to put into place laws to stop this kind of extreme and selfish activity ... by a small group of protesters hell bent on wreaking havoc," she said.

Australian Associated Press