Despite the newfound serenity of commuters' journeys, London transport authorities have continued to urge passengers to plan ahead with a warning that Friday will be the busiest day of the Games period. Friday has long been identified as the likely traffic peak, with weekday travel to work coinciding with the opening of the athletics at Stratford, an event that will involve a huge increase in numbers heading for the Olympic Stadium. Transport for London (TfL) dismissed claims of a deserted capital by saying figures showed overall tube journeys were up 10% this week compared with the same time last year. Passengers entering and leaving West End stations were up 12%. Peter Hendy, the transport commissioner, said: "This Friday and Saturday will be the busiest days of the Games so far, as the Olympic Stadium opens its doors and sporting events continue to take place across the capital." There are three athletics sessions at the 80,000-capacity stadium on Friday,. TfL expects about 250,000 people to travel to the Olympic Park, with the underground's Jubilee and Central lines doing most of the work, but it emphasises that there are eight other rail routes should either of these lines fail. A spokesman conceded there had been "different patterns of activity" in London's transport system this week, but said it was "still a very busy network". "We are seeing people travelling less in the peaks, but more use in the afternoon and evenings – that's the advice we gave people and they are responding to that." Travel by Oystercard – the discount swipe cards used by the majority of Londoners – was slightly down. Spectators have been issued with Travelcards along with Games tickets. The Westfield shopping centre next to the Olympic Park will be closed to all but Games spectators for for Friday and Saturday, but Hendy – conscious that retailers have been blaming messages to avoid London for a slump in trade – stressed: "London has a rich and vast array of other attractions to offer during the Games, so I encourage everyone to enjoy the theatres, restaurants, shops, free concerts, Live Sites [big screens where people can watch the sporting action] and attractions and to continue to use GetAheadoftheGames.com to plan your journeys." Bar minor periods of disruption to the Javelin high-speed service from St Pancras, caused by a trespasser, and a stoppage on the Central line because of an electrical fault, London's transport services have functioned smoothly since the start of the Games. TfL advises spectators watching the athletics to travel to West Ham, the next station to Stratford on the Jubilee line, to avoid the crowds.