Tens of thousands of Sydneysiders are on their way out of the city, slowing traffic to a crawl and triggering fears a small coronavirus outbreak in NSW's north could grow.

Footage taken from the 7News chopper showed hundreds of cars crawling along the M1, north of Sydney, as people prepare to spend their long weekend out of the city.

All of the main roads leaving Sydney, including the Hume Highway in the west, and the Western Highway heading towards the Blue Mountains also slowed to a crawl.

NSW Premier Gladys Berejiklian yesterday warned the state to respect coronavirus restrictions over the Easter long weekend.

"The good news is everything is still open," she said.

"We are just asking people to respect the four-square metre rule, just until the end of Easter and make sure they're sitting down when they're having lunch or dinner."

The Byron region is especially popular with holidaymakers in NSW with fears the small cluster there could be picked up by someone this weekend and taken somewhere else in the state.

Follow our blog for live breaking news updates throughout the day.

RELATED: What's open this Easter long weekend

Originally published as Fears as thousands escape city for Easter