Attendees at Vivid Sydney say they felt "trapped" trying to get home after larger-than-expected numbers attended the festival's drone show on Saturday night.

Vivid Sydney has drawn huge crowds to the CBD during the past two weeks.

Following last night's drone show, many attendees claimed they became "trapped" near the Overseas Passenger Terminal.

Police said a larger-than-expected number of attendees resulted in congestion, particularly in and around transport hubs.

Crowds dispersed after a short period and there were no injuries or incidents reported.

Images posted to social media show the Circular Quay foreshore tightly packed with revellers.

'Quite confronting to see'

Student Anthony Warren travelled from Melbourne to attend the drone show at Circular Quay.

He said he was worried "something bad" was going to happen as people tried to leave the area.

"There was a crowd of people without any explanation," he said.

"People didn't know where to go and started to crush."

He said he could not see any crowd control people but he saw police officers disassemble metal barricades.

"People with babies, prams, elderly people — I noticed some were quite distressed. It was quite confronting to see." 

'It was human sardines'

Former NSW government minister Victor Dominello attended the drone show and said crowd control was "non-existent from what I saw".

'It was human sardines," he said.

"No-one anticipated how many people would be on the foreshore."

Vivid Sydney organisers urged attendees to plan their visit.

"Vivid Sydney organisers work with government partners and agencies to plan and deliver a successful and safe event, including to manage the crowds that turned out to see last night's drone show," a spokesperson said.

"We understand that a large number of people leaving a major event at the same time can be slow and challenging and are grateful to the public for their patience and cooperation."

Extra police on duty

Health Minister Ryan Park this morning said extra police would be on duty tonight for the second drone show.

'It's an incredibly popular event. It's a long weekend. It's good weather at the moment, people are out and about," he said.

"Police advise that there was a lot of people there, a lot more than expected."

Mr Park advised people not to go to the foreshore unless it was necessary.

"We're saying to people that if you can see the city, you'll be able to see the light show. 

"You don't have to be right down there at the foreshore."

A peak tourism and transport group has said locals were flocking to major central business districts across the country for leisure rather than just for work, especially in Sydney and Melbourne.

Margy Osmond from the Tourism and Transport Taskforce said people were flocking to the cities on week nights and weekends.

"What's happening here is that people are viewing the city as somewhere you go to have a good time whether it be a festival, whether it's going out to dinner or bringing the kids in to see the sights," she said.