Like the entire race itself, crossing the street at the Boston Marathon seems to be a very organized affair.
A time-lapse video posted to YouTube Monday shows how race volunteers carefully herd people from one side of the busy race route to the other, in a kind of ballet that aims to allow people to cross the route while runners don't have to miss a stride.
The process goes like this: A pair of marathon volunteers stand in the road, facing oncoming runners, and use two yellow signs with blue arrows to warn race participants that they need to stay to one side.
Several other volunteers help stretch a long rope along the road to block off the area where they don't want marathoners to run.
Once that section of the road is cleared, pedestrians on the side of the road are then shuffled in a large group to the middle of the street, where they congregate in a box outlined in white on the pavement.
The pedestrians stay in that box as race volunteers repeat the same process, this time using the rope and signs to funnel runners to the other side of the road. When the coast is again clear, race attendees make a mad dash for the other side of the street.
Then the whole process begins again as more people arrive to cross the course.
The video, which was also posted to Reddit, has been viewed more than 800,000 times. It shows crowds moving across Beacon Street in Brookline.
As of Tuesday morning, it was the "number 2" trending video on YouTube, according to the video website.