The New York City Marathon is an engineering marvel
The first thing Ted Metellus did at the end of the 2021 New York City Marathon, besides getting a good night’s sleep, was start planning for this year’s race. “It’s on my mind all the time,” says Metellus, race director and vice president of the New York Road Runners (NYRR), which organizes the race. It was last February. Spanning five boroughs in the country’s largest and densest city, with as many athletes on the course as would normally fill the stands at a sporting event – although it also has several thousand spectators – the marathon is a complex negotiation of time, space, and people. “This is one of the biggest resource mobilizations in the city,” says Metellus.
In number, it is impressive. Last year, even with a reduced pandemic field of more than 21,000 runners, some 41,240 gallons of spring water from Poland – and 1.4 million paper cups – were distributed to runners on the course (in more than 45,000 bottles and more distributed at the start); as well as 30,000 Honey Stinger gels. Some 122,760 pounds of clothing was thrown away by runners at the start, then collected and turned over to Goodwill. There is a medical station every kilometer, even therapy dogs and psychologists at the start. “Sometimes people just need a moment to settle in when you’re preparing for an event of this magnitude,” says Metellus.
This year, the marathon is back in force, with more than 50,000 participants expected in the streets of New York this Sunday. The task of figuring out how the people of this small town will travel the 26.2 miles from Staten Island to Central Park – and making sure it happens with as little friction as possible – falls largely to Marcel Altenburg, Master of lectures in crowd science at Manchester Metropolitan University. German-born and former Bundeswehr captain Altenburg traveled to Manchester to earn a degree in crowd science, a discipline he notes that really got its start in 1989 with the infamous Hillsborough stadium disaster. , when 97 people were killed in a crash caused by overcrowding. He stayed and became a lecturer.
Since then he has been involved in many high-profile events, from presidential inaugurations to rock concerts to football championships and most recently managing the massive crowds queuing to pay their respects to Queen Elizabeth. . And, of course, a number of marathons, from Berlin to Chicago. In 2016 he began working with the NYRR on the world’s biggest race. At 8 a.m. on Sunday, when the first wave of athletes – the professional hand cyclists – hit the course, Altenburg will be at the start village, looking to see if his deliciously calculated scenario plays out as planned.
The starting process itself is massive: it will easily take longer to distribute the five waves of runners, in 15 “corrals”, over three starting points, than it will take for the best runners to finish the race (it takes 18 minutes, less than a pro can run a 5K, just to distribute each group). And the beginning, from a planning perspective, is everything. “This is the last moment we can influence the race,” he said. “This is the last time anyone will listen to you, the last time we can tell them, stay straight, wait a second. From there, the race is on them.
It’s a bit like a water tap. You can control the source, but once the water is flowing, you can’t easily call it back. When he started working with the Road Runners, he had a revelation. “We were convinced that how we start had an impact on the whole course,” says Altenburg. “That everything on the course is of our own making.”
Once you accurately modeled the beginning, you could predict, with unprecedented accuracy, everything that happened next. After rethinking data from previous years, Altenburg said moving to 15 corrals, instead of 12, would allow for better control. He told Metellus: “If you give us the start, we can predict the finish and the 26.2 miles in between.”
Dividing the race into five-minute windows, Altenburg predicted that the largest finish wave would consist of 1,366 runners. There were 1,367. “I know who the guy was,” laughs Altenburg. “He was from Mexico.” But his overall estimate was 99.93% accurate. The code had been cracked, its “Start Right” predictive algorithm born. Now, any contingency that might arise — even a global pandemic that suddenly required six feet of social distancing — could be modeled.
The rolling start, as opposed to the “open start”, is now fairly de facto at most major international marathons, but some races, Altenburg notes, “are in love with that big crowd image at the start of the race – a guy pulling a gun, and everyone starts at the same time. But that’s no longer possible in the bigger events. “The races are bigger,” he says, “and the cities certainly don’t get bigger.”
With chip timing, he adds, “they don’t have to be at the start line – you can start two hours later and still get your finish time.” The key to this, he says, is to make the starting point narrower than anything they will experience on the course and keep the “water tap” only 70% open. It’s a bit like the “access counters”, those traffic lights that tell you when you can enter the freeway. Basically, we go slower to go faster.
What sets a marathon apart from other crowd management scenarios is its dynamic nature. Although it’s essentially a rolling queue, it’s a queue, says Altenburg, “in which everyone is constantly changing the order of everything.”
Compared to even a big event like the Queen’s funeral, which saw over 250,000 people, “a marathon is, to be honest, 50,000 times more complicated”. With something like a football game, the crowds can be massive, but the behavior is usually constrained. “I have to get them in, it’s a big task. I need them to sit down, then go to the bathroom, then go home. These are all big steps, he says. “But in a marathon, they never sit down once.” They arrive “by all means of transport”, then circulate around the village of departure, then they take the road, then they finish, grab their poncho, and try to find their family or their friends. “Fifty-five thousand people make their way in shorts, and each has their own story, each at their own pace.”
Marathons, indeed, cannot be understood as a system. Armed with massive amounts of computing power, data from previous races, and the hope that people will run more or less at their advertised pace, Altenburg must calculate every runner. “The ideal experience is that I see the same 100 people for most of my run,” he says. “The organizer goes to great lengths to minimize the number of overtakings on the course.”
Being constantly overtaken, or conversely having to constantly “zigzag” past groups of other runners, is not only stressful, he says, but can be dangerous (algorithms predict an ideal three square meters for each runner, a number that was briefly increased in the age of social distancing). The professional field, says Altenburg, “will expand immediately,” while riders further back could spend more time together. But people are not data points, they will do the unexpected. They are chaotic. I speak here from experience. When I entered the event in 2017, impatient and under-trained, I ran a fairly fast half-marathon, passing many runners – which often wasn’t easy on the narrow streets of Brooklyn – before to slow down in the second half and basically explode at the end. While my finishing was statistically average, I was, on a more micro level, often an outlier.
And then there is the city itself. “It’s the same race every year, the name is the same, but New York is a living organism,” says Altenburg. Pavements are changed, massive construction sites spring up, new cycle paths are built; all things that might not affect the individual runner, Altenburg says, but might have system-level implications. During the pandemic, street food restaurants have emerged and many structures have remained, further limiting the streetscape (for some, NYRR is asking for temporary closures). Every five years, the route is meticulously measured.
In conjunction with the city’s Department of Transportation (DOT), NYRR conducts a number of course inspections in the months leading up to the event, flagging potential obstructions. “We don’t allow steel plates on the roadway,” Jessica Colaizzi of DOT told me. “We’re very firm on this and we’re working closely with contractors to make sure the plaques go away.”
Then there are things that are beyond anyone’s control, but still need to be considered, like the weather. This year’s event promises above normal temperatures. “As the temperature increases by five degrees Fahrenheit, we run a different simulation,” Altenburg says. Medical resources can be moved to potential hotspots (temperatures above 70 degrees, as promised on Sunday, are associated with a high risk of heatstroke).
For the professional field, Altenburg says, it won’t matter much – they’ll be finished by the time warmer temperatures set in. But for everyone else, it could have an impact. And not just, says Altenburg, for slower, later runners. “You may not be a professional, but someone who knows what he’s doing and wants to break the three-hour barrier. It’s exactly when it’s hot, when you go to your limits.
While each runner organizes their own race, Altenburg has observed some global trends regarding the New York City Marathon over the years. “People always speed up when they get to Manhattan,” he says, “even if the advice is not to, you still have eight miles to go!”
But another trend is that as the race gets bigger, it actually slows down. “They attract a lot of people who see it as a bucket list race,” he says. “It’s slower because it’s more inclusive. It’s an amazing race, and you want to do it at least once. Altenburg himself ran it, in 2015. But in his head, and on his computers, he still makes it work. “As a scientist, it’s bananas. I love that.