The rush of New Year's travelers returning from their hometowns reached its peak Monday, in time to return to work today -- when most companies reopen for business. However, the number of train and airplane passengers returning to Tokyo and other big cities was smaller than usual, probably because Y2K concerns kept many at home -- or in the office. According to East Japan Railway Co., most trains heading for Tokyo on Monday morning had vacancies, except for the Asahi No. 4 bullet train from Niigata. The U-turn rush peaked in the afternoon, a company official said. As for air travel, all domestic flights bound for Tokyo were nearly full. Japan Airlines had some vacancies on flights from Sapporo, but all of its other flights were full, a JAL official said. All Nippon Airways had reservations for 98 percent of its seats on flights bound for Tokyo and Osaka. The number of passengers on ANA during the New Year holidays was about 2 percent lower than average because of Y2K concerns and also because some people instead opted to travel on the coming three-day weekend that begins Saturday, a company official said. The longer weekend is the result of a new law that has made the dates of some national holidays flexible so that they can be observed on Mondays. Coming-of-Age Day, a national holiday traditionally observed on Jan. 15, has been moved to the second Monday of January beginning this year. Traffic jams began Monday morning on major roads and highways leading into the Tokyo metropolitan area. The trail of tail-lights lengthened as the day progressed, but the backups were relatively shorter than normal, according to highway operators. Meanwhile, at Osaka's Kansai International Airport, families bearing gifts from their holiday travel destinations abroad crowded the arrival lobby on Monday. According to the airport's immigration bureau, the number of returnees peaked Monday at about 20,000, about 3,000 more than last year. But the total number of people traveling abroad during the holiday season between Christmas day and Jan. 4 is expected to fall about 8 percent, or 30,000, due to Y2K concerns, authorities said. "The fireworks were so pretty at the countdown over the Thames River," said 23-year-old Yuka Matsushiro of Kobe reflecting on her five-day trip to London. "It was wonderful."