How to Design the Perfect Queue, According to Crowd Science

“There’s a significant amount of math and formulas that has been written about this over the years,” says Still, “but that doesn’t take into account psychology.” There are both positive and negative elements at play when it comes to the psyche of this particular queue. Almost no one within it will ever have waited as long for something in their lives, meaning they could quickly become frustrated.

But for die-hard royal fans determined to pay their respect, there’s another risk. “One of the concerns that has always been foremost is that if people are standing for 20 hours, then they may push themselves beyond their limits,” says Still. Three hundred people in line have been given medical assistance, with 17 taken to nearby hospitals, according to the London Ambulance Service.

While Kant says that the queue can’t, by definition, be described as perfect, the 14-hour wait times are not as bad as you might think. The government’s queue-tracking livestream, which gives the estimated physical and temporal length of the line, provides transparency about how long people can expect to wait. It means anyone can go in open-eyed about the challenge ahead of them—even if it has had its hiccups, including directing people to start queueing in North Carolina. The queue tracker is augmented with regular updates on social media that tell people where to start lining up, or indeed not to bother as the queue reaches capacity.

The queue is a challenge for infrastructure, too, with more than 1,000 people—including 779 stewards and 100 volunteer marshals—ensuring no one cuts in. Along the queue route, 500 portable toilets have been installed, while a wristband system is in operation allowing people to leave the line to get food and drink and not lose their place. A separate, shorter queue for those with disabilities has stewards checking anyone who is flagging in the main line, then siphoning them off to the shorter one.

For the accessible queue, the UK government has borrowed a model from theme parks, many of which offer timed return slots and priority access for paying customers, with a limited number of timed slots available every day. They’ve also borrowed another element from the likes of Disney: entertainment. BFI Southbank, a cinema run by the British Film Institute located on the last mile of the line before it arrives at the Palace of Westminster, is showing archive footage of the queen on giant screens outside its building.

Setting expectations is also vital, and another lesson learned from theme parks. Estimated wait times make the world of difference, says Still. “Queueing systems such as at Disney, Universal, and Six Flags all consider this,” he says. “It’s all about keeping the crowd entertained, informed, and distracted.”

Another concept borrowed from theme parks are the snakelike sections that double back on themselves to allow more people to be crammed into less space, which are visible not only at Southwark Park but also Potters Fields Park, around one-third of the way into the line, and closer to the conclusion of the queue. These need barriers and staff to help make them work.

“It’s just fortunate that this has happened now, after the summer,” says Collinson. “In the middle of the festival season, when it was in full swing, it may have even been harder to get the infrastructure and the stewards.” Such ways of lining people up make the queue seem shorter than it is—a clever psychological trick to try to ease frustrations.

But one surprise has been the comparative lack of disquiet about standing so long in line. Rebellion hasn’t materialized in the form of cutting in or complaints about delays. If anything, people have been more annoyed about not being able to join the line in the first place. The queue for the queue is evidence of that. “I just call it determination,” says Kant.