LONDON (AP) — Queen Elizabeth II’s lying-in-state will be an occasion of regal symbolism, strong emotion — and an extremely long line.

Marshaling the hundreds of thousands of people who want to view the late monarch’s coffin will test Britain’s famous queuing skills to their limit.

Authorities overseeing the mammoth logistical challenge have consulted queue management experts and behavioral scientists to create not so much a line as a temporary community. It features 10 miles (16 kilometers) of “queuing infrastructure,” including moveable barriers and more than 500 portable toilets along a route leading to Parliament's Westminster Hall, where the coffin will rest.

Hundreds of stewards, police officers and first-aid volunteers, 30 multi-faith pastors and two sign language interpreters are assigned to look after the welfare of people waiting in line.

The queen’s coffin is scheduled to travel Wednesday from Buckingham Palace to Westminster Hall, where it will lie in state from 5 p.m. (1600 GMT) until 6:30 a.m. (0530 GMT) on Monday, the day of her funeral.

Hours before the coffin had arrived, the line of mourners already stretched from Parliament across nearby Lambeth Bridge and snaked along the south bank of the River Thames. The designated route stretches for 6.9 miles (11 kilometers) past the National Theatre, Shakespeare’s Globe, the Tate Modern art gallery and Tower Bridge to Southwark Park in south London, which can accommodate another 3 miles (4.8 km) of zigzagging queues.

Officials say they can’t predict how many people will line up to pay their respects at Westminster Hall, but it is likely to be many more than the 200,000 who visited the Queen Mother Elizabeth’s coffin over three days in 2002. Transit operator Transport for London estimates that more than 1 million people will travel to the city center to be part of commemorations through Monday.

Transport for London Commissioner Andy Byford called it “the biggest event and challenge that TfL has faced in its history.”

The government has warned that navigating the line will be a feat of endurance.

“You will need to stand for many hours, possibly overnight, with very little opportunity to sit down as the queue will be continuously moving,” it said in a set of detailed instructions for those wanting to come.

People will be able to check the line’s length and waiting times on the Department for Digital, Culture Media and Sport's social media accounts. Those joining will be given numbered wristbands so they take food or toilet breaks without losing their place. A separate accessible line has been set up for people unable to stand for long stretches.

As ever in Britain, jumping the queue is a definite no-no. Officials hope mourners’ sense of fairness will make the line largely self-policing. Given the vagaries of British weather, people are advised to carry both an umbrella and sunscreen.

The government is offering other helpful hints: Bring food and drink, but be sure to consume it before reaching the front. Bring a portable power pack to keep phones charged.

When they reach Parliament, people will pass through airport-style security scans. Prohibited items include large bags, liquids, spray paint, knives, fireworks, flowers, candles, stuffed toys and “advertising or marketing messages.”

Those in the queue on Wednesday were convinced all the hassle would be worth it.

“To give up my day queuing is nothing compared to what she’s done for 70 years,” Gina Carver from Tunbridge Wells in southern England said of the late queen. “And she does feel like our grandmother.”

Follow AP coverage of Queen Elizabeth II at https://apnews.com/hub/queen-elizabeth-ii