Expo '70 in Osaka received 64,218,770 visits over 183 days. With 116 pavilions across the site, waiting became routine at the most popular attractions. The United States Pavilion, where visitors came to see a Moon rock, became one of the defining lines; a study reported that 38 percent of surveyed visitors to it had waited more than two hours.
Visitors had to judge not only the queue in front of them but congestion across the entire grounds. Waiting-time information boards therefore displayed conditions at individual pavilions. A device now familiar in theme parks and transport systems served as an information tool for distributing people through an enormous exposition.
What distinguished the Expo '70 queue was that waiting to see future technology became an experiment in crowd-management technology. The future on display included not only a Moon rock and audiovisual spectacles, but also the ability to choose where to queue next by reading a number.