The Tōkaidō Shinkansen began service on 1 October 1964, in time for the first Tokyo Olympics. The conventional Limited Express service took six hours and 40 minutes from Tokyo to Osaka, but the Shinkansen made the trip in just four hours, shortened to three hours and ten minutes by 1965. It enabled day trips between Tokyo and Osaka, the two largest metropolises in Japan, significantly changed the style of business and life of the Japanese people, and increased new traffic demand. The service was an immediate success, reaching the 100 million passenger mark in less than three years on 13 July 1967, and one billion passengers in 1976. Sixteen-car trains were introduced for Expo '70 in Osaka. With an average of 23,000 passengers per hour in each direction in 1992, the Tōkaidō Shinkansen was the world's busiest high-speed rail line. As of 2014, the train's 50th anniversary, daily passenger traffic rose to 391,000 which, spread over its 18-hour schedule, represented an average of just under 22,000 passengers per hour. The first Shinkansen trains, the 0 series, ran at speeds of up to 210 km/h (130 mph), later increased to 220 km/h (137 mph).