Spectators lined up along the route to watch the trials

More than 180 competitors rode the 7.9km time trial prologue from Whitehall to The Mall, taking in landmarks such as Buckingham Palace.

About 4,500 police officers guarded the London leg of the race with assistance from a team of 45 French officers.

Security has been heightened after last week's suspected car bomb attempts in London and Glasgow.

The trials started at 1500 BST and ended just after 1800 BST.

This is the first time the speed trials, also known as the Grand Depart, have been held in London.

Road Closures Whitehall Parliament Street Parliament Square Millbank up to Lambeth Bridge Broad Sanctuary Victoria Street Buckingham Gate Spur Road Constitution Hill Hyde Park Corner Grosvenor Place north of Hobart Place Park Lane south of Curzon Gate Continental colour hits streets

Police Superintendent Ian Chappell said "We have reviewed our measures to make sure they are appropriate and respectful of the Tour de France's tradition as an open event, a free event."

Hyde Park was transformed into a village with a giant screen and numerous food stalls.

Eighteen other giant screens were also put up along the route.

Starting at Whitehall, cyclists sped along Parliament Square, Victoria Street, Buckingham Gate and Constitution Hill before finishing at The Mall.

Whitehall, Parliament Street and Victoria Embankment, will be closed throughout the weekend while most of the roads along the route will remain closed until 2100 BST.

Other roads which will be closed are: Kensington Road (east of the Royal Albert Hall), South Carriage Drive, West Carriage Drive, Serpentine Road, Pall Mall, Pall Mall East, Haymarket south of Charles II Street, Cockspur Street, Strand, Trafalgar Square, Charing Cross Road south of Cambridge Circus and Northumberland Avenue.