People have been warned to avoid driving in parts of London on the day of the Queen’s funeral.
One of the UK’s largest transport operations will take place on Monday, with around one million people expected to visit the capital.
Road closures on the A4 and A30 will begin to enter from 6am, with full closures in both directions after 10am, which will likely not be lifted until the evening.
There will also be multiple closures on local roads along route A4.
People wishing to drive in central, west and south west London are advised to check before traveling, allow more travel time and expect long delays.
Bus lines will also be severely affected with many routes diverted or stopped before their destinations.
Andy Lord, Chief Operating Officer of Transport for London, said: “We know London will be very busy tomorrow and we advise everyone to check before their trip.
“If you can avoid driving in London tomorrow, we strongly recommend that you do so, as there are a significant number of road closures in place and travel will take much longer than usual, especially in West London.”
Some road closures will last until the evening.
Around 250 extra rail services will be operational, including some night trains, and National Highways has suspended planned motorway closures across England.
The transport network is feared to be overwhelmed on Monday afternoon if too many people visiting the capital return home soon after the funeral procession leaves Westminster shortly after noon.
TfL chief Andy Byford told PA news agency: “We are ready for probably one of the busiest days Transport for London has ever faced.
“It’s hard to say exactly how many more people (will travel), but we’re preparing for potentially a million people right within the footprint of the royal palaces and Hyde Park.”
Byford said TfL “leaves nothing to chance”, with non-essential meetings postponed and people from across the organization working to ensure visitors can “get around town”.
Network Rail President Sir Peter Hendy warned that the trains will be “extremely busy”.
He said: “This is the largest public transport operation since the London 2012 Olympic and Paralympic Games and we are working closely with all rail operators to run extra trains during the day and night.
“To help us provide the best possible experience and avoid long lines at stations, we ask people not to rush home after the funeral and processions, but to take their time and experience London on this memorable day.”
Network Rail has postponed engineering work and keeps its London stations open overnight to provide shelter for mourners struggling to get home.
All night trains only serve limited destinations, mainly within the M25.
Stationary trains are used as waiting areas early in the morning for people waiting to catch a train home.
Priority will be given to elderly and vulnerable mourners.
Three tube stations – Westminster, St James’s Park and Hyde Park Corner – will remain closed for much of Monday morning to avoid overcrowding.
More than 100 flights to Heathrow Airport will be canceled to prevent aircraft noise from disrupting work at Westminster Abbey and Windsor Castle.
West London Airport announced that 15% of its 1,200 flights taking off or landing on Monday will be disrupted.
British Airways, the most affected airline, has canceled 100 short haul flights due to restrictions.