Hundreds of thousands of people are set to flock to the centre of London to celebrate King Charles' Coronation next month.
The historic event on May 6 will see the largest military ceremonial operation in 70 years, with more than 6,000 men and women of the UK's armed forces taking part, and around 10,000 people attending a concert at Windsor Castle on the following day.
Charles and the Queen Camilla will make their way back from Westminster Abbey in the Gold State Coach via Parliament Square, along Whitehall, around Trafalgar Square, through Admiralty Arch and down The Mall back to Buckingham Palace.
Transport for London (TfL) has urged travellers to "plan ahead" and allow more time for journeys than normal, saying services will be extremely busy.
Temporary safety measures may be put in place such as queuing, closures, trains not stopping at certain stations or changes to the way people enter or leave a station.
And for any royal fans hoping to catch a glimpse of the procession, the Department for Culture, Media and Sport (DCMS) has advised not to arrive before 6am due to fears of overcrowding.
It said: "You should be aware that large crowds are expected, and be prepared to queue to enter the viewing areas. Follow the directions given by stewards and the police, who will monitor crowd numbers and ensure everyone can enter safely and securely.
"Capacity at the viewing areas will be limited and they will be closed when they are full. If you leave a viewing area at any time, readmission cannot be guaranteed."
The viewing areas have limited capacity and may close before the events begin, added the government department.
It also issued guidance on how to stay safe in crowds, urging people to follow directions given by police, take care of their belongings and report anything suspicious.
People are urged to avoid travelling immediately after the events, with plenty of trains running throughout the day and late into the evening.
Andy Lord, London’s Transport Commissioner, said: "We are delighted that London is hosting ceremonial events for the Coronation of Their Majesties King Charles III and Queen Camilla, and look forward to welcoming visitors and Londoners alike onto the transport network for this historic occasion.
"We expect central London to be very busy and the large-scale events will mean road closures in central London, so I’d advise people to check before they travel.
"I’d also encourage Londoners and those visiting to mark the celebrations to make the most of the public transport options, as there are no planned closures."
It comes as extra train services are being laid on for the coronation weekend, but the transport operation will not match what happened for the late Queen's funeral.
Great Western Railway said it will run some "very early" additional services to London Paddington from major stations in south Wales, south-west England and the Thames Valley area on May 6.
It will also operate an "enhanced service" between Windsor and Slough on May 7 and the early hours of May 8 for concertgoers.
South Western Railway said it will run its usual timetable on the day of the coronation service, but there will be additional trains between London Waterloo and Windsor for the concert.
Govia Thameslink Railway - which operates Gatwick Express, Great Northern, Southern and Thameslink - said its services will have more carriages than normal on May 6.
There is no planned engineering work affecting lines serving London or Windsor during the weekend.
Many train companies are not planning to enhance their operations for the weekend as much of the additional passenger demand is expected to come from within the South East.
That means the transport operation will be slimmed down compared with the late Queen's funeral in September last year, when around 250 extra train services ran, including some overnight.
Major stations in London were kept open overnight to provide shelter for mourners waiting for trains home.
