According to a live-update feed from the British government's Department of Culture, which is managing the queueing system for the Queen's lying-in-state, with a little less than an hour to go until the Palace would start to admit visitors the queue had already reached two and a half miles. This was up half a mile in just 30 minutes at the time of writing.

The public part of the lying-in-state will commence 1700 (1200EST) London time Wednesday and run through to the early hours of Monday morning, 24-hours-a-day, at which point the hall will be closed for preparations for that day's Royal Funeral.

While the rapid growth of the queue may slow once people are being admitted to Westminster Hall to pay their respects, as the working day ends and the public have more free time the line may surge again. The same impact will likely be felt come the weekend, when many will travel from across the country, from Europe, and from the world, for a chance to pay final respects.