45-Minute Bus Trip Turns Into a Four-Hour Fiasco LONDON - As Olympic organizers saw it, Monday was to have been the day when things finally started to go right in a countdown to the Games that has so far been something of a public relations disaster, mostly given the fiasco over too few security guards - thousands too few - and the emergency deployment of British troops to replace them. And in many ways, matters went swimmingly - until, as the first contingents of athletes were transported across London to the Olympic Village, they went spectacularly wrong. By the end of the day, organizers were struggling to explain how three buses carrying dozens of athletes, officials and journalists to the Olympic Village from Heathrow Airport lost their way in the maze of London's streets, causing one American medal hopeful, the 400-meter hurdler Kerron Clement, to post a Twitter message in desperation after four hours aboard a bus that should have made the 24-mile journey in 45 minutes. Athletes are sleepy, hungry and need to pee. Could we get to the Olympic Village please," he wrote as the driver, struggling to understand the route given by the bus's GPS device, finally abandoned repeated forays up dead-end streets and pulled out a map. Not a good first impression London," Mr. Clement added. The misrouted buses episode came as thousands of competitors and team officials began arriving at Heathrow on a day that officials said was the busiest in the airport's 60-year history. There were none of the three-hour immigration backups that have plagued the airport in recent days, raising fears of gridlock with the opening of the games only 11 days away. Instead, travelers passed smoothly through passport control, many in just minutes. The main M4 highway into London was open again after the completion of emergency work on an unstable flyover that had closed six miles of the route for two weeks, and traffic moved smoothly along the miles of "Zil lanes" - dedicated parts of the main roads across London that have been set aside for the exclusive use of Olympic officials and V.I.P."s, named after the Russian-made limousine and the Soviet custom of reserving road space in Moscow for top Communist Party officials. Many of the 100 Olympic venues were officially opened, and while there were glaring examples of no-shows among the private security details, extra troops and police officers who were drafted to replace them began to rebuild confidence that the Games would be properly protected. Last week, acknowledging that the private security contractor G4S was going to be several thousand guards short of its commitment to provide 10,400 guards for the Games, the government announced it would add 3,500 troops to the 13,500 already preparing for Olympic duty. And then there was Mr. Clement, the American hurdler, twice a world champion and the silver medalist at the 2008 Olympic Games in Beijing. Before boarding his transatlantic flight, he had brimmed with optimism. "It's always exciting seeing other athletes on the flight to London," he posted on Twitter. We are all after one thing. But Mr. Clements's account at the end of his journey was far different, as the only thing he seemed to be seeking was a long-overdue meal, a bed and a bathroom. Similar dire accounts came from Australian athletes and officials, fresh from a 20-hour flight. Damian Kelly, a spokesman for the Australian delegation, described their bus driver as desperate in his apologies when their journey to the village also ran on, for about four hours. "The driver just said, "I'm sorry, I'm lost. It's my first day on the job and I'm lost," " Mr. Kelly said. We were moving, we were in the Olympic lane, and we were going places, we just weren't going where we were supposed to go. None of this seemed to perturb London's mayor, Boris Johnson. "I understand that some of our visitors took the scenic route," he told the BBC. They saw more of our fantastic city than they would otherwise have done. And that's no bad thing. The mayor added, "What thing of beauty "does not have its imperfections?"