CROWD PLEASER
Four Majors set finisher records in 2024. Meet Marcel Altenburg, the crowd science guru who helped make the biggest bigger
By Louise Sylvester
The 2024 TCS London Marathon took a quantum leap in finisher numbers when more than 51,000 runners arrived on The Mall, smashing the previous year's high of over 43,000.
Five months later, the BMW BERLIN-MARATHON had its 'hold my beer' moment, setting a new world record of 54,280 in its 50th year.
Celebrations were short-lived. On November 3, the TCS New York City Marathon surpassed its fellow Major with 56,646 coming home in Central Park.
The common demoniator in all of those record fields was one man.
Marcel Altenburg, a Senior Lecturer at Manchester Metropolitan University, is one of the world’s foremost experts in crowd safety and risk analysis. With a passion for understanding how and why crowds gather, move, and behave, he has dedicated his career to ensuring large-scale events run successfully and safely.
Born and raised in Germany, he spent 12 years in the armed forces, rising to the rank of captain. His time in the military instilled in him a deep understanding of logistics, crisis management and decision-making under pressure - skills which would later prove invaluable when he transitioned to civilian life and discovered a love for running and major events.
His entry into the marathon world was serendipitous. In 2009, he interned at the Berlin Marathon. Recognizing the complexities behind managing thousands of runners over a sprawling city course, Marcel was asked to support the event’s control room, where he played a crucial role in ensuring the marathon ran smoothly. Over the next three years, he honed his expertise in solving real-time challenges, often applying the structured thinking he had developed in the military.
He later pursued a master’s degree in crowd science at Manchester Metropolitan University. With access to major marathon data and real-world challenges, his studies bridged the gap between academia and the practical demands of large-scale event management. "My partnership with Abbott World Marathon Majors when studying was incredibly beneficial – having full access to control rooms and their data meant that from the get-go this wasn’t just an academic course, it was linked to real life problems and ambitions in the marathon industry."
The Algorithm
At the heart of Marcel’s work is the revolutionary Start Right algorithm; a tool he developed when studying at Manchester to optimize crowd flow and event safety. Used in hundreds of events annually, it has transformed how marathons and other large-scale gatherings are planned and executed.
During the 2019 Berlin Marathon, the algorithm helped reduce end-of-race congestion by nine per cent, shortened the event’s impact on the city and allowed 4,500 additional runners to participate. Similarly, at the London Marathon, Marcel’s insights led to a 30 per cent increase in runners while reducing density at key pinch points like Cutty Sark by 40 per cent.
The key to this success lies in data. The algorithm incorporates start times, course layouts and runner pacing data to predict crowd flow. This allows race directors to deploy resources (such as aid stations, portable toilets and medical personnel) exactly where they’re needed. It also ensures that runners and spectators enjoy a safer, more seamless experience.
Marcel has helped reduce runner density at key pinch points like Cutty Sark by 40%
"Seeing people cross the finish line, achieving what they thought was impossible - that’s the best moment for me.”
A Special Place in his heart
For Marcel, marathon events are 'Nirvana'. “There’s so much energy in these events; it’s hard not to be excited about being involved at any level,” he says. As a lifelong runner, he understands the joy and determination that runners experience on race day. However, from a crowd science perspective, marathons also present unparalleled challenges. Marcel works with all seven Abbott World Marathon Major races in planning and is present for five of these events in the control room on race day.
Unlike stadium events, where attendees remain relatively stationary, marathons involve dynamic movement over hours and miles. The courses are often ‘pop-up events’ built from scratch, requiring extensive coordination. Marcel’s algorithms help organizers understand how the start connects to the finish, anticipate peak densities at specific points, and maintain smooth operations across the 26.2-mile course.
A highlight came when New York organizers challenged him to predict how many runners would cross the finish line during their busiest five minutes. His calculation? 1,366 runners. The actual figure: 1,367 - a near-perfect prediction.
Expanding Beyond Marathons
Marcel’s expertise extends far beyond running events. His crowd science work has contributed to a wide range of high-profile events, including: The Dubai Expo, where he optimized queuing systems to ensure minimal wait times. He was also involved with the Queen’s Lying-in-State in 2022, where his predictive models calculated queue lengths and waiting times with astonishing accuracy - within 50 meters and 14 seconds!
His models have also been applied to other industries, such as football tournaments, Formula 1 events, and even the Olympics, showcasing the versatility and impact of crowd science.
Feeling Proud
Marcel’s work has not only made marathons safer but also more inclusive and enjoyable. By optimizing crowd density, he has enabled events to accommodate more participants while enhancing the overall experience for runners, spectators, and volunteers alike.
One of his proudest achievements came in London, where his strategies allowed more runners to participate while giving everyone more space on the course. “It’s great to grow with demand, but when you can improve the experience at the same time, it’s a win-win,” Marcel reflects.
London Marathon’s Race Director, Hugh Brasher, said in 2024: “Our event grew by more than 27 percent since 2019. While the density for the individual runner did not go up. At certain key points the runner density is reduced by up to 28 per cent compared to 2019. All of this was done based on simulations and optimization of resources.”
The Future of Crowd Science
In 2016, an email conversation between the Majors Race Directors at the time said: "This simulation and science could change the entire industry.” And so looking ahead, Marcel is excited about expanding the use of crowd science to emerging markets, particularly in Asia and Australia, where marathons are rapidly gaining popularity. He has also been instrumental in helping the Sydney Marathon transition from a local festival to an event with global ambitions and its new-found Major status! It has grown from 13,000 to 20,000 finishers in its two years of candidacy, and is expecting to welcome 35,000 runners on the start line this year.
A Lifelong Passion
Despite his intense schedule, Marcel still finds time to participate in smaller marathons and ultra-distance races, often running in the same cities where he works. “After seeing everyone take part, it’s hard not to be inspired,” he says.
When asked about the most exciting aspect of his job, Marcel told us: “During the race, I’m in the control room, managing dots on a screen. But afterward, I watch the highlight reel, and it never fails to bring tears to my eyes. Seeing people cross the finish line, achieving what they thought was impossible - that’s the best moment for me.”
Marcel Altenburg has not only transformed how marathons are managed but also how crowds are understood. His work ensures that events worldwide are safer, more efficient and more enjoyable for everyone involved. Marcel’s expertise will shape the future of crowd science - one step, and one runner, at a time.
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