There will be travel disruption due to the Royal Parks half marathon taking place today.
Road closures include Hyde Park Corner, Parliament Square, Victoria Embankment and Westminster Bridge, with a number of bus routes also affected.
TfL is advising drivers to avoid the area if at all possible as it has caused "serious delays" in the past.
Full details of the closures and how best to get around are on the TfL website here.
The Royal Parks half marathon takes in four of London's best known parks - Hyde Park, Kensington Gardens, St James’s Park and The Green Park.
The route began in Hyde Park at 9am, heading through Green Park and on past Buckingham Palace into St James' Park. It then moves across Embankment taking in the Houses of Parliament and the London Eye.
Finally it loops back round through Admiralty Arch and Kensington Gardens before finishing back in Hyde Park.
The Royal Parks half marathon is underway, with 16,000 people racing through four of London's best known parks.
The 13 mile route is expected to take a minimum of one and a half hours to complete by the fastest runners.
When the sun comes out, Londoners head to the parks by the thousand.
But all that extra use has taken its toll on the Royal Parks deckchairs, and there's more hot weather on the way, so 6,720 of them will have their old canvas stripped and recycled into reusable bags. .
That means two miles (4,700 metres) of new canvas has had to be ordered. Enough to stretch from Buckingham Palace to Primrose Hill.