Met to deploy 3,000 officers on New Year's Eve
Some 3,000 police officers will be out in London on New Year's Eve for one the busiest nights of the year.
Up to 250,000 people are expected to gather in the Southbank area to watch the London Eye fireworks display.
Officers will be deployed at street level and on podiums to give them a bird's-eye view of any troublemakers.
Trafalgar Square is another popular place for revellers to meet at midnight.
Ch Supt Julia Pendry, of Scotland Yard, said: "Make sure you look after yourself and those around you. Officers will be out and about to deter criminals and keep crowds safe.
"New Year's Eve in central London is extremely busy so do come prepared and wrap up warm, as you may have to wait to prevent overcrowding. The viewing area does fill up really quickly and each area will be closed off by the organisers once it reaches its capacity."
She urged people to consider watching the fireworks on TV instead as sometimes the viewing area fills up as early as 2000 GMT.
Ch Supt Pendry urged those planning to party in areas like Leicester Square and Trafalgar Square to be prepared to walk to Tube stations further away, like Waterloo or Charing Cross, to avoid being stuck in massive queues to get home.
All travel in London will be free from 2345 GMT on New Year's Eve until 0430 GMT on New Year's Day. Road closures will be in place in the city from 1600 on 31 December.
Ch Supt David Wildbore from the British Transport Police (BTP) said: "If you are travelling into London on New Year's Eve, you need to be prepared.
"It could be cold, so be prepared for that and plan your journey. Don't drink too much and stay awake on your journey. That way you will have a good night out and arrive home safely."
BBC Radio 1 DJ Nihal will entertain the Thames-side crowds before the firework display begins.
Those wanting to see the pyrotechnics have been warned however that visibility may not be good.
Gareth Harvey, a forecaster with Meteogroup, said: "It looks like it will be cloudy on the night but temperatures should remain mild, with the chance of a few spots of drizzle."