The final English leg of the Tour de France starts later with nearly 200 cyclists racing along the 96-mile (155km) route from Cambridge to London.
Riders in the short third stage will leave Parker’s Piece in Cambridge at 12:15 BST and pass through Essex.
The race will visit Saffron Walden, Chelmsford and east London, going past the 2012 Olympic Park, before ending at the Mall at about 15:45 BST.
About 2.5m people lined the Yorkshire route over Saturday and Sunday.
Vincenzo Nibali, from Italy, won the second stage between York and Sheffield to take the yellow jersey after cycling along 201km (124m) of gruelling roads and hills.Germany’s Marcel Kittel claimed the first stage victory, between Leeds and Harrogate, on Saturday.
The Grand Depart from Leeds was officially started by the Duke and Duchess of Cambridge and Prince Harry.
British rider Mark Cavendish crashed out of the race near the finish line of Saturday’s first stage and injured his shoulder, putting his Tour to an end.
The peloton will pass famous landmarks, including Cambridge University’s St John’s, Trinity and King’s colleges as well as London’s Tower Bridge, Big Ben and Buckingham Palace, opposite the finish line.
In Essex, big screens showing the race have been set up at Felsted, Finchingfield village green and Chelmsford’s Admirals Park.
Some streets around Cambridge will be closed from Sunday evening and all vehicles are banned from the city centre from 07:00 BST.
Road closures will also affect the boroughs of Redbridge, Waltham Forest, Hackney, Newham, Tower Hamlets, City, Westminster, Lambeth and Southwark, Transport for London (TfL) said.
Streets along the London route will be closed at 10:00 BST and will reopen in phases up until about 18:00, police said.
In 2007 more than one million people lined the London route to watch and cheer 189 riders at the opening ceremony, time trial and first stage.
TfL has advised spectators who plan to watch the Tour to check for road closures and disruptions.
Magenta signs have been placed along the route and at stations to direct spectators to areas where they can watch the cyclists.
Fan Parks have been created in Green Park and Trafalgar Square and a spectator hub at Hopkins Field in the Queen Elizabeth Olympic Park, where giant screens have been set up.
London Mayor Boris Johnson said: “I wish every rider taking part in this gruelling endeavour the best of luck – I’m sure they will no doubt inspire even more Londoners to take to two wheels.”
Mounted Branch officers will patrol around St James’ Park, with stewards across the route, Met Police said.
There will be 18 more stages before the race reaches its final destination of Paris on 27 July.