Police will be using buses and garbage trucks as safety barriers at Sydney's huge New Year's Eve celebrations, to avoid a Nice or Berlin-style attack on the expected 1.5-million-strong crowd.

NSW Police said more than 2,000 officers would be rostered on tomorrow night to keep revellers safe, including Water Police, PolAir, mounted police and general duties officers, as part of Operation Talisman.

There will be 18 command centres across the greater Sydney area.

While police said there was no specific threat to New Year's Eve events, they were aware of a number of risks, especially following the Nice and Berlin attacks where people used vehicles to crash into crowds.

Assistant Police Commissioner Mick Fuller said a whole of government response was being taken to ensure the safety of those celebrating.

"The threat level is at probable and therefore from our perspective it is important that we look at all potential risks, whatever crime that may be," he said.

"Vehicle-borne threats is one of those and we've certainly spent a significant amount of time mitigating any vehicle-borne threats."

Man arrested after alleged online threats

A 40-year-old man was arrested at the Sydney Airport on Thursday and charged over making threats online targeting Sydney's New Year's Eve festivities.

Acting Deputy Commissioner Frank Mennilli said the man did not have links to any cultural groups, and that he was charged with a Crimes Act offence, not a terrorist offence.

"The person has acted in isolation," he said.

"The matter is still under investigation and there may be some further charges, but I can certainly assure everyone there is no current threat from that individual or any other person."

1.5 million people are expected to attend Sydney's New Year's Eve fireworks. ( AAP: Mick Tsikas )

Revellers advised to plan ahead

Commissioner Fuller said they had spent 12 months planning for the event and recommended those attending to take a few minutes to plan their night.

He recommended checking the City of Sydney website, livetraffic.com and to take advantage of the extra public transport that would be put on for the night.

"But at the end of the day please don't come in expecting you will get to a vantage point later in the evening," Commissioner Fuller said.

Acting Deputy Commissioner Frank Mennilli asked revellers to drink in moderation.

"New Year's Eve is a time to enjoy with friends and loved ones, all security measure have been addressed to provide a safe environment for everyone, but at the same time it becomes personal responsibility and people making right choices," he said.

"Drink in moderation, don't drink and drive, don't become involved in antisocial behaviour and that way you won't become a victim or offender."