Managing Participant Flows

Have you ever wondered how the choices you make about your race start procedure can affect every aspect of the rest of your race? Even simple things, like choosing a wave start over a rolling start, or changing the order and size of each wave, or the width of your start line, can have a significant impact on your race’s safety, congestion on the course, and even your staffing requirements for aid stations and your race finish area.

Today I have the pleasure of having as my guest Marcel Altenburg, probably the world’s foremost expert in crowd dynamics for mass-participation events. Marcel is a senior lecturer at Manchester Metropolitan University and has helped countless races optimize their participant flows from start to finish. Marcel has so much experience in this area and we’ll be going over some simple rules Marcel has come up with from his research that you can use to optimize your race start procedure - whatever the size or type of your race.

In this episode:

• What is crowd science and how it can be applied to the study of participant flows during mass-participation endurance events
• How your start line procedure affects everything that happens downstream at your race race course
• Always try to order start waves by pace (faster runners at the front, slower runners at the back), even if you can't do it perfectly
• Make your start line 30% narrower than the narrowest point on your course to avoid congestion
• Aim for a max 3 people per sqm in your start pen for a safe, comfortable race start
• Keep start waves of slower runners at the back smaller than start waves of faster runners at the front
• Prefer rolling starts over open starts to eliminate the uncertainty of people arriving at random times
• For socially-distanced races, keep participants sufficiently socially-distanced at the start and they will only spread out further during the course

Thanks to GiveSignup|RunSignup for supporting quality content for race directors by sponsoring this episode. More than 22,000 in-person, virtual, and hybrid events use GiveSignup|RunSignup's free and integrated solution to save time, grow their events, and raise more. If you'd like to learn more about GiveSignup|RunSignup's all-in-one technology solution for endurance and fundraising events visit runsignup.com.

You can find more free resources on planning, promoting and organizing  races on our website RaceDirectorsHQ.com.

You can also share your questions about start line procedures, participant social distancing or anything else in our race directors Facebook group, Race Directors Hub.

Transcript

Panos: 0:07

Hi! Welcome to Head Start, the podcast for race directors and the business of putting on races. Have you ever wondered how the choices you make about your race start procedure can affect every aspect of the rest of your race? Even simple things, like choosing a wave start of a rolling start, or changing the order and size of its wave, or the width of your start line, they can all have a significant impact on your race's safety, congestion around the course, and even your staffing requirements for aid stations and your race finish area. Today I have the pleasure of having as my guest Marcel Altenburg, probably the world's foremost expert in crowd dynamics for mass- participation events. Marcel is a senior lecturer at Manchester Metropolitan University and has helped countless races optimize their participant flows from start to finish. Marcel has so much experience in this area and we'll be going over some simple rules he's come up with from his research that you can use to optimize your race start procedure - whatever the size or type of your race. Before we go into all that though, a quick shout out to our podcast sponsor, GiveSignup|RunSignup, the leading all-in-one technology solution for endurance and fundraising events. More than 22,000 in-person, virtual, and hybrid events use GiveSignup|RunSignup's free and integrated solution to save time, grow their events, and raise more. And, a bit later in the episode, we'll be quickly touching on a couple of really great free tools GiveSignup|RunSignup have to offer to help you smoothen the process of checking in participants on race day, so you avoid the crowds, the queues and the headaches. Okay, let's get into this amazing episode. Marcel, welcome to the podcast.

Marcel: 2:01

Hey, Panos. How are you doing?

Panos: 2:02

I'm very well. Thank you. It's a pleasure to have you on today. I understand that you are quite a busy guy these days in the middle of a global pandemic, working as a crowd scientist. So you work at Manchester Metropolitan University which - as you were telling me the other day - is the Hollywood of crowd science. So tell us a little bit about what do you do in your day job? And what do you do as a crowd scientist and what are the kinds of problems that you look at?

Marcel: 2:31

Thank you, Panos. First of all, I need to pick that up - the Hollywood of crowd science. I keep saying that because I would have never thought that I'd end up here in Manchester. I'm actually from Berlin, Germany. And I came to Manchester because that is the focal point of crowd science. Anyone who wants to focus on crowds in events or in mass gatherings needs to, at one point, learn from our university here, or get in contact, or inevitably come across Manchester Metropolitan University. So it is the Hollywood of crowd science - the one point that everybody needs to come across. And that's also what brought me here - to study here, basically. There's a Master of Science, the world's only unique Master of Science in crowd dynamics and risk analysis that brought me here. And I stayed here because the university didn't let me go. I supported the course. And now it took over the course. And I'm teaching this Master here from Manchester to the whole world. Like, we have students from all over the world.

Panos: 3:33

And in terms of the work you guys do at the crowd science program, can you give us, like, a brief description of the kinds of problems you look at and what it's all about?

Marcel: 3:44

Yes, 100%. We know very well from daily experience that not everything can be solved just by having students in front of us and teaching them the fundamentals of crowd science. Sometimes, you need a solution within days. Everybody who works in events knows that you cannot have a problem and, then, go somewhere to study it for three years to, then, solve it. Sometimes, you need to find a crowd dynamic solution for your unique problem within one season or within a few days. And that's what we do. We teach, obviously, I mentioned that. But we also have a consultancy aspect where we directly work with race directors, with event organizers, with public transport, and so on. We support them in their changes. We make it part of our research. We also leave them directly usable advice. We help them implement changes to solve their problems, as I said, sometimes, within days. For me, that's one of the reasons why I stay in Manchester. We have a direct connection to the industry. We are part of life challenges on a daily basis. Those lessons become part of our research. So although we might have solved an issue, we still research it. We still make it a part of our interest here because we are a university. And, then, eventually, they will find its entry into teaching so that we can learn collectively because, way too often, when I as a single event organizer have a problem and I solve it, I'm so happy that I'm over this challenge, but I won't tell anyone afterward. Or I might head to the next problem. And it will never become like a rule that others can apply it, that others can learn by the pure nature of our busy industry.

Panos: 5:38

Right. So what kinds of problems-- for example, in the context of what our listeners would be most interested in that is endurance events and mass participation sports, what kind of problems are you trying to solve by looking at crowd dynamics?

Marcel: 5:54

Yeah. I gave you three examples. And the last one will be the segue to road races. I want to, first, start with something that's, literally, happening this year - the Expo 2020 in Dubai. That's like the biggest World Fair Expo ever. It's record-breaking. It has the biggest budget and things that we have never seen before in terms of its pavilions and its whole layout. So with all those words that I just mentioned, all those like superlatives, this is not something that you can test beforehand, and this is not something that you can take another experience from other events. You need to make it up, build it in stone with a hefty budget, and then it needs to work. So something we experienced alone wouldn't carry it the whole way. And that's something that we do. And, then, obviously, we have the luxury of learning from what's happening at this massive World Expo. Another one that is relatable to that would be things like airports. We all know that the demand on an airport is constantly changing. Even before COVID, obviously, there are constantly different standards. Every airport worldwide, if you talk to the staff, they're stretched to the limit. And they're all planning the next version of the airport that somewhere down the line, like, maybe, in 10 years, they're going to build a new one. In between every year, every month, there are different demands on the existing structure but you cannot change it. You basically need to grow within your shell like a crab. You need to grow within your shell and find a new way to use what you have because it takes 10 or 20 years before you can, basically, grow the infrastructure. You still need to grow within what you have by optimizing. And airports are a great example of that. And that brings us to road races. We call it hyperdynamic in road races because - compared to a theater event, or even airports, or football stadia - nobody ever sits down. So everybody's moving down the course, or to the start, or out of the finish. So everything is constantly moving. And everybody is moving at their own pace. It couldn't be more like thousands of ants having different time goals in mind. So we do basically the same. We help events to grow and change safely. It doesn't always need to grow in terms of capacity. It can also be changed because the city infrastructure change, or you cannot have the course as last year. Something is different than last year. And you need to know what does that means for the overall movement of 5,000 people, or 10,000 people, or more. So those are the things that we look at to support great individuals, great race directors. They identify a problem. They can point at it, read, support, give us the resources that we have, and the niche interest into crowd science on a daily basis.

Panos: 8:57

So you're trying to, sort of, anticipate and solve things like bottlenecks, or the very crowded finish line, or how people get off the start line. Are these the kinds of issues that you look at in the context of a road race, for example?

Marcel: 9:17

Yeah. You hit the nail on the head here. It could be like a bottleneck. That's the very obvious one. You might incur a new bottleneck on your course that may be due to a construction site. Like anyone who has a city race or races, they know you need to check for construction sites. You even need to check for construction site containers on the road that, kind of, narrow your road all of a sudden compared to last year. So a lot of those things. But it could also be a new course that you need to investigate because, maybe, you have an inaugural race. Or maybe parts of your course can't be used like last year. There are very few races that can, basically, go with the same plan as last year. But it could also be different things. It could be a safety issue. It could also be optimization. So when we talk about aid stations and staffing, there might be a way to reduce or to optimize your staffing by adjusting something on your crowd flow from the start, which could then also, in the end, increase the experience for everybody. If I give an example, if you have like a traveling peak - basically, the peak of the highest density on the course and - some runners might be within this peak for the whole race and they have an entirely different experience than those that are running or traveling behind the peak or in front of the peak. So maybe there is a way to even this out, give everybody the optimum experience, and also make this work for everybody on the course - every staff member, every aid station, every security guy, every guy who hangs medals around necks - and make their experience better by optimizing the course.

Panos: 10:52

Well, yeah. And you were telling me - actually a really interesting example, which may not sound particularly grand - that by simulating crowds, I think it was the Berlin marathon, you guys helped to trim down the amount of time that roads had to be closed for like 10 minutes, which again, may not sound huge, but in the context of a whole city, like being released to traffic 10 minutes earlier is a pretty big achievement.

Marcel: 11:18

It is. Yeah. That was an example that we discussed earlier which it was in a year that Kipchoge broke the world record in Berlin. But that for me was, basically, a win from a crowd science perspective. By optimizing the crowds there, we were able to reduce the overall flow by close to 10%. So if you work at an aid station, post-finish, you would think, "Hey. This is less. This is not as fast as last year. It might even be less people." But there was actually more people than the year before but the flow was much more even. And that was felt by everyone there. Plus, as what you've just mentioned, we were able to get rid of one wave at the end. So instead of making it five waves, we made it four waves, which - our research showed us in this particular case - made more sense. It's counterintuitive. That's due to the nature of 45,000 people all having on their own agenda, with their own plan in mind. But yeah, if you can give the road back 10 minutes earlier to the city officials, that makes for a good surprise at the end. It makes them happy, it makes the relationship better, and that shows that you optimized what you're doing. If you have more runners, it's less busy for everybody involved. They're better at using their workforce and they can have a more relaxed day. Plus, you save time. That makes for optimization.

Unknown: 12:37

And I

Panos: 12:37

think Yeah. And we'll go into some really, really useful tips. You have developed some rules as to what people should do at start lines that everyone can learn from in order to make the whole process smoother and everything. And we'll go into that soon. So I watched one of your talks like 2-3 years ago or something in which you were explaining the benefits of crowd dynamics. And I remember, back then, that you talked about, "By simulating crowds in a race, broadcasters know where to place the cameras" and everything. And, of course, now after going through COVID, I guess some of those priorities have changed a little bit. So how has COVID changed the focus of your work?

Marcel: 13:21

Yeah. COVID changed the work with road races and also the work with every event. My focus is mainly on events and sports. I'm a runner myself. I have worked with road races for more than 10 years and I cannot get away from that. And there are lots to learn and also lots to use from other events. And especially with COVID - social distancing started very early at the beginning of the pandemic - we all tried to figure out what does it mean for us when there are certain restrictions of, "This is how many people you can put in one square of 100m x 100m" or like, "How much space do you need to give everybody in terms of feet or square meter and so on?" So we needed to assess how much should we give them, actually, in order to see how far are we away from any restrictions, and how close are we in order to like talk to city officials and prove that we are, either, on the right side already or we can get there. And due to our past works with big road races for many years, we realized that we actually have this information. We actually know how many people on our course are within 100 meters or 100 yards, or within one minute, anywhere on the course at all times. We do have this information to screen the whole course for people within any bracket of time or space. And that means that - with the width of the road - we can then, actually, also make out how much space do we give to every individual, and that gave us the start of a dialogue. First of all, it gave us information for our own planning and, then, we adjusted. While we were adjusting, it gave us the chance to talk to officials, to authorities, tell them of all the plans and why there was, in the beginning, a lot of fear, a lot of unknown about the pandemic, and what that means for us. It gave us, very quickly, the chance to talk to city officials, get them on board, and change a lot of those unknowns to facts. That might still lead to the result that we cannot have the race but we, at least, know how far we're off. And it also left quite early through the first green lights. Like, New York has already started to return to racing projects in the fall of 2020, which went over the whole winter and, in the end, will bring us to a, hopefully, successful New York City Marathon at the end of this year. And there are all those races. There's all those research done with us in New York, Chicago, and Berlin. And marathons like those gave us a chance to use what we learned in like big-scale races, take this knowledge, give it to others, share it with our friends and partners in Canada, in Europe, and Australia, and use it for the entire industry. That's a very long answer to your question - what we've done during COVID.

Panos: 16:13

Yeah, indeed. And we'll get into some of those lessons that you've put together in the five golden rules for race starts. I think there's plenty of useful stuff there. One thing to mention here is that all of this analysis you guys do, you make available to organizers through a sort of company that you've spun off from all the research that's called Start Right. Can you tell us a little bit about that?

Marcel: 16:38

Yeah. So first of all, we are a university and we want to teach, and share, and research. And that's basically what drives us forward. And we realized that, in the road racing industry, there are like so many races. Every one of them is unique. They have a unique course. They have a unique mission. They have very unique runners that they attract. So while sharing lessons, guidance, or principles, we also need to find a way to cater individually to each race with their unique audience during the course. And for that, we developed an algorithm that can use all of those unique information that most race directors have, like timing data, certain course states, and so on. And this algorithm learns from everything we do and can give advice. You can look at the course and you can adjust anything. You can put in restrictions. You can put in changes and it answers your questions, basically. It simulates your race. And the demand for this was quite high. We are supporting around 100 races per year with this service. And that was too much for our university, I must admit. And so that's why we said, "Hey. Let's have this separate entity that's called Start Right" and that allows us to support races very flexibly. So, like, whenever they need us, sometimes, they call us a year in advance to talk through changes. Sometimes, they call us two weeks before the race and say, "Hey. There's one thing that we need to solve or one thing that we need to prove to authorities. Can you help us?" And we try to be more flexible than the university can be by offering the service.

Panos: 18:21

Yeah, I actually saw some really impressive simulation videos of Grandma's Marathon from Start Right where you can actually see, sort of, like, little dots of people coming into the start line in waves, then they set off, then another wave comes on. And you can see all kinds of data like, exactly, where the peak density of people is over the course and how they then hit the finish line. So it's like having the race playing out in front of you.

Marcel: 18:52

Yeah, definitely. Grandma's Marathon was in a very unique situation this year. That's the race that happened in Minnesota in June. And they were a race that a lot of people looked at because - there were some races before that - that was like the first race that was a taster for what the fall season might look like. The fall season is very important for the running industry. We all, kind of, know that this one needs to work better than last year. So that was the first race that is already called a post-COVID event, which sounds so good and fragile at the same time. But, yeah. We threw all our support at Grandma's because we knew of the importance. It used this software that I just mentioned - Start Right. It used everything that we learned. I mentioned that we have like, 100 races per year, which is like around a million runners. A million runners' results per year that we're using to teach our algorithm that I would learn from. As much as I love running data, a million is too much for me to fully grasp, so we need to get technology to do that. And all of this improves what we can then use for supporting something like Grandma's. We would normally adjust a start slightly or adjust the capacity of a race by increasing or changing something slightly, like slight adjustments from one year to the next. Now, there's COVID. And you had to change on a massive scale so much. And that's why we have Grandma's Marathon to see, "If I change something here, like, at the start, what does it mean for the rest of our course? Maybe something big that I've changed only has like, a slight difference for the whole of the race. Or maybe it's something tiny that I can change that doesn't cost me a lot but it makes a world of a difference down the line on the course." We sometimes compare starting a race to a water tap. I can do so many things at the start. I can open it entirely with a lot of water - a lot of runners coming out - and, then, close it again. I can do it in waves - I can just open it a bit and let them trickle out. And all of this will have a difference for the course. It's really hard to spin your head around what changes it makes if a finish is 26.2 miles away from the start. You need some calculating power and experience to do it. And that's what we had with Grandma's. Their race was successful and conditions improved since then. And conditions are evolving and changing. And, yeah. They gave us good hope for the fall season.

Panos: 18:53

I guess what you're saying there is that, if the course is what the course is and, then, runners are people that - depending on their capacity - can run faster or slower, really, it all comes down to how you manage the start line. That sort of affects everything from that point onwards.

Marcel: 22:05

It is. And, also, I always say, "It's the last time they listen to you." Like at the start, early in the morning, your team members are at the end of their training at the start of the race. They listen to you because they want this to go right. They don't want to waste a second. They want to do the right thing. They want to go but also do not want to go. But once they cross the start line, that's it. They can't listen to you anymore and they shouldn't. They should do the thing that they came for - an uninterrupted race. They shouldn't need to stop anywhere because it's a tight spot or because you need them to do something. And they should run the entire race. So the last time that you can change something for every individual is before the start. And runners really listen, really cooperate, and they do what you say at the start. And, then, they should do their own thing. And all of those runners with their individual time goals and their individual career that they started, they all together make the flow. There's a lot of mixing, a lot of things happening within the flow. And to get this right, you only have that chance at the start. And, then, the rest is hopefully, hands-off, watching what's happening. And you don't need to adjust anything along the way.

Panos: 23:20

Yeah. So let's look at the start line then. And let's look at what as you were saying - more than a million data points with runners and hundreds of races have taught us - about how different choices of how you start your race lead to different outcomes, in terms of people traveling through the course and finishing. And you have put together a set of five golden rules, in terms of what you can do for your race start to better manage the flow of people and keep everyone safe and distanced. So rule number one you have on your list is, "Make sure you order your field by pace." So I guess you mean putting your fastest runners at the start and, then, the slower runners at the back.

Marcel: 24:15

Yeah. We really want to share something out of what you just correctly mentioned based on more than a million runners and data sets per year. So we're constantly learning from this and that is research that was done over the last five years. And there's a report to this which, I think, is around 200 pages by now. But we wanted to share this with everybody and that's why I'm so happy to be able to like share this with your audience on this podcast and also in writing to really give away some of the lessons that we learned from this research. A lot of things might sound familiar and might be intuitive. Others are maybe counterintuitive. But this gives a race director some signs, some proof to their hands to, basically, prove their intuition and ensures that, "Yeah. You are you on the right track and we can explain why," and to share this with, like, races of any capacity. And that's what this works for. The first point is order. It doesn't matter if you have a 200 people race or a 50,000 people race. If you can order them, from fastest to slowest, that will be the ideal, because that makes perfect sense probably. When you think about it, it reduces the number of overtakes on the course. If I have the fastest in the very back of, like, maybe, a 200 people 5K race, the fastest will probably end up the first but he needed to go through all the 200 people. And this works to any degree. If you put him somewhere in middle, he only needs to overtake 100 people, and so on. But the main point here is you will never succeed, probably, in ordering them perfectly because people have, maybe, a bad day or good day. Or maybe you only have three waves. You order three waves by pace as best as you can. But then within the waves, you cannot really order them without breaking that pace down - but that is not the point. The point is any sort of order helps. And even if you have your 5K with 200 people somewhere in the forest, even if you break that down into two groups, just bring a bit of order. It will help because it increases the degree of order. We're not talking about having an order or not - that's not the point. The degree of order by any bit helps. And if a race of 20,000 says, "Hey, we will up the number of corrals or pens that we have and order them a bit more," that will have an impact. And if those volunteers at the entrance of every corral make sure to double-check and let people know, "Hey. You're here in the wrong corral. You're in the wrong pen. Yours is over there." They will make sure that everybody is in the best possible position throughout the entire race among folks that have similar abilities. He won't be overtaken that much which is stressful for him and for everybody who needs to run past him. And to wrap this up, there were - races where every individual was involved in a thousand overtakes, like we can measure all of this - prominent city races where people were involved in a thousand overtakes either by people coming past them, or they having to find their way through the crowd and, then, we are able to reduce this to around 200 or maybe 300. You get a feeling of, like, how that helps every individual to have a more relaxed day and be more in tune with their own ways. But, also, every time people overtake each other, they'll run abreast for a second or two. And when they run abreast next to each other, I need more course width. So there's an absolute benefit, basically, of ordering them just a bit so that they don't try to go through another section of a course when they're overtaking and by reducing the number of overtakes.

Panos: 28:05

Yeah. And, of course, less people overtaking is also, generally, good for health considerations now - with COVID and stuff.

Marcel: 28:14

100%. You said that absolutely right. And my main point is any degree or order helps. So any volunteer at the start, you can make a difference to the whole race if they, at the start, send a couple of people to the right pens and, like, focus on that, you can change the whole course and you can change the whole finish long after you're part of the event that you were responsible for is over. The result of that will still be felt. And if you are a race that thinks about, "Should I have corrals? Should I order them a bit?" Yeah. Any degree helps. You don't need to change the world. Just any bit helps. That's what our research shows. And I think I went into enough depth to make that point,

Panos: 29:03

I guess you should order people either through past data or most likely, sort of, like, self-declaration stuff. So you collect information. I've seen it on registration forms where you'd ask people, "What's your pace? Or what's your expected finish time?" What about people that you don't have data for?

Marcel: 29:22

Yeah. That's a very good point. So that's what I mentioned, like any degree is beneficial. And that could either be by proof of times, like a 10K time or a half marathon time and so on, or by projected finishing time. It doesn't really matter. As long as you ask everybody the same thing, "Do we have an expected finishing time? Or do we have proof of one thing?" They will find a way to order them. Any order that you don't do at the start needs to happen on the course. That's what overtaking is. If you let them run for a thousand kilometres, in the end, they will arrive very exhausted, but they'll also arrive in the perfect order. So if you are able to do this at the start, even better. So those who you don't have data points, maybe, you can ask them, what are their career times, like of a 5K and 10K if they don't have a half marathon time in this example. What you shouldn't do is put all the newbies, all the first-time runners in the last wave. That would not be a way of ordering. That would be a way of logistically managing it in a way that would cause disorder, like, more than necessary.

Panos: 30:29

It's interesting because, actually, I was about to say that's exactly how I've seen some races I've run in the past manage people without times. Usually, what they do is they put them all at the very last wave. I guess you can have people of all kinds of abilities in there. And, I guess, probably for logistical reasons, as you say, they just throw everyone at the back of the pack, which may not be optimal, perhaps.

Marcel: 30:56

Yeah. I've been in those corrals in the back as well. That was a long time ago. Now, there is-- I don't know. You cannot even walk without something on your body counting your steps. So if there is any way to assess your pace - it doesn't need to be perfect - that can be used.

Panos: 31:17

While we're on the subject of managing crowds, one of the areas that always gets people concerned is packet pickup. "Is it going to run smoothly enough?", "Am I going to get everyone checked in and on their way fast enough to avoid getting those long check-in queues people hate?" Well, GiveSignup|RunSignup have really made an art of race-day check-in, and with their free RaceDay CheckIn App the process of checking in runners and getting them their swag has never been more efficient. You can quickly get people checked in with pre-assigned bibs, if that's what you like to do, or you can use the amazing dynamic bib assignment functionality. What's great about that is, instead of frantically looking for the right people on race-day, you can assign runners bibs at pickup - whatever bib might be on top of the pile. All the runner has to do is come up to the table with their QR code from their confirmation email on their phone, get it scanned by one of your volunteers, and they get a bin number assigned to them instantly and their swag order delivered in seconds. And you know what the best bit is? With dynamic bib assignment, there's no more wasting bibs on no-show runners. You only give out the bibs you need to the people actually starting your race - no waste and no money down the drain. It's so neat how much you can do with technology these days that we should actually probably dedicate a full episode on just race-day check-in. But that will have to wait. Now, let's get back to discussing more of Marcel Altenburg's golden rules for efficient race starts. So rule number two for efficient starts is that your start line should be 30% narrower than the narrowest point of the course within the first two kilometres. So that's pretty specific. That's also something that people would have guessed. How did that come about? And like what's, sort of, like, the logic or the intuition behind that?

Marcel: 33:15

Yeah. That's basically the first challenge that we had when we did our big research on crowd flow. Our first main challenge was if we have a pinch point on the course - there was an inaugural race that we had here in London and there was a pinch point on the course and - the question was, "How to fit through the pinch point?" which led us to what you mentioned earlier, "How to start?". That has been the main challenge. And on a big scale, we solved this with an algorithm. But if you don't need the algorithm, a good rule of thumb to go by is, obviously, before the start line, people are at a higher density than they can run. Let's forget COVID for this example. People are standing quite closely to one another. They're listening to some good tunes. There's a countdown. They are standing at a density that is not normal that wouldn't work in a supermarket and definitely wouldn't work while running where they need more space. In order to give them that much space, you need to give them space on the course, basically. That's what you do here. So if you reduce the start line, basically, to go back to the example of a water tap, reduce how wide you open that tap, that means they are trickling on the course slower. So when less than, let's say, a thousand people enter the course within a minute, it may just be 700 people, those 700 people now have more space than a thousand in the same minute, basically. And that space is vital for them to be able to run. Like if somebody is too close to me, I cannot fulfill my stride, which is probably more than two and a half meters per second. So I need that space in front of me, physically, in order to be able to run and have a quality experience. But the crowd science lesson that is behind that is you need to give people space before they can move. Sometimes, in the event world, it's the other way around. People move to create space. That's not the case. It's the other way. It's like we need to give people space in order to move. That's what we do here. By reducing the flow - like, instead of opening the tap entirely, open it just to 70% - that means they do have enough space to run at their pace and to fit through anything on the course. That is as precise as we can do to fit it into a few rules. When we calculate something like this for, let's say, Chicago Marathon, or Berlin, or New York, we screen the entire course. We have precise measurements of every bit on the course. And we check the start against all those pinch points on the course. That was done with pen and paper, maybe, eight years ago. And, now, we do these 12 million calculations to be really sure that everybody fits through there. But in one sentence, "Yes. 30% less than the narrowest point on the course should be your start line." And one last thing, this doesn't mean that the start entry needs to be 30% less. It can be a pinch point before. It can be like a funnel before you actually start entry. So a start gantry has a standard format over the course of the road, over the whole width of the road, and it says your sponsor. 10 meters behind that, or 5 or 20 meters behind that, you can have a funnel built of fences and that should be 30% less.

Panos: 37:02

So, basically, at some point during the start flow, just make sure there's like a funnel which is a maximum of 70% of the narrowest point throughout the course. So rule number three, "Keep the density of people within the start pen at a maximum of three people per square meter." So my first question on that is - is that compliant with, like, typical COVID distancing requirements these days?

Marcel: 37:35

Not with COVID. Hopefully, when we return to racing as it was before, then you will need to put three people per square meter. As I said, I need space in order to be able to move and that's what we aim to achieve here. There is some guidance out there that says four people per square meter which we, from a science perspective, can say it is wrong, it doesn't work. So although there might be numbers circulating out there, no race ever does that because it doesn't fit, it wouldn't work. Three people per square meter - that's something that we want to give race directors a number at hand that is scientifically proven, and that they have a basis to plan on. So three people per square meter is good. Very quality races go to 2.1-2.3 people per square meter. So they give them even more space, which we found in surveys, that's very well received by the audience if they do have this extra space at the start. As for four people per square meter, I invite everybody to try it having four people per square meter at home. Try to tie your shoes if you stand in a quarter of a square meter. It's impossible. So that is a safety aspect. So here in this case, I mentioned to you before the podcast that we do a lot of work also with stadia, like football clubs here like Manchester City or United or Bayern Munich. And this is something that comes from their neck of the woods that comes from the world with them. Like, how much space do I need to give people in order to feel safe and very important? So even if something goes wrong, they won't react in a stressed way, but also be safe. And we're talking about emergency here. I'm talking about evacuation. I'm just talking about general safety that if one person falls, that doesn't mean that everybody falls like a domino. And three people per square meter is a safe middle ground between using my space efficiently, but also giving everybody a safe space no matter how big my race is.

Panos: 39:36

Do we know what that number would look like these days with COVID? Like, what density and social distancing rule should we adhere to, for instance, like two meters in some places in Europe, or six feet or whatever in the US?

Marcel: 39:53

Yeah. That is a very cool topic because that is what makes or breaks a race. I need to give them 10 times that much space than what we've talked about here for, let's say, two-meter social distance. When there's a queue in front of my supermarket here in Manchester because of social distancing, the queue is now longer, maybe, double the length than it was before without social distancing. But if I have a crowd, I now need to keep the distance, not just to the guy in front of me and the guy behind me, I also need to keep the distance from everybody at my left and right. So the space is growing in both directions. So if I double the distance for a roadway start, instead of one meter to two meters, let's say - this is a real-life example, we had to change it here in the UK - that will be quadrupling the space that they need just because they need to go in both directions and that is even without a safety buffer. And that makes it, very quickly, not a viable undertaking anymore, if I need to give them four times as much space between one meter and two meter or - in this case, between normal and COVID - six and ten times that much space. Like, you wouldn't find that. I don't know your specific ways but I doubt that you'll find an extra 10 times that much space.

Panos: 41:16

So, basically, if you really try to design a grid of people that appear two meters between all of them, you'll probably look at - if you said 10 times more - something like three people per ten square meters or something, which is quite a lot.

Marcel: 41:34

Yeah, definitely. So yeah, that's what you would look at. And all these, like, fulfill those rules. And that will break a lot of people's event because what we also found in our research that social distance, if we look at like, one meter, two meters, or three meters on the course for all our road races-- we looked at a hundred races last year and they all fulfilled social distance requirements on the course, having five or ten meters distance between runners. It is a start that needs to be nailed - post-finish, and on the course, road races don't have that problem. They fulfill the requirements. It is the start aspect where you need so much more space. And the difference between the two meters that we have here in the UK and the 1.5 meters that we had, let's say, in Germany, or parts of Europe is massive. As I just said, like the quadrupling of distance plus multiplying it with the high number of participants can make or break an event. So when we change it here from two meters to one meter in the UK, that is a different world entirely. And even the difference between six feet - which checks out at around 1.80 meters to 2 meters difference - is making such a big difference on a large scale event. I sometimes think those rules are introduced for good reason. They seem to be super even, more even than scientists would do it - the one or two meters something. That's easy to digest. But just centimeters here per person changes if a race can go ahead or not.

Panos: 43:13

So in terms of having to do race starts with some degree of social distancing that goes beyond the normal distancing, you would allow in your third rule three which is, like, maximum three people per square meter on the basis of keeping people comfortable on the start line when it was pre-COVID. Have you seen any special protocols being put together for race starts that would allow racers to start with social distancing at even large races?

Marcel: 43:50

Yeah. We have a lot of races put on a start with social distancing rules in different formats. It could be a time-trial start where like, five people set out every few seconds, or where individual corrals have like 100 or 200 people set off at one goal and then there's the next ones, or maybe even all of them walking up, like zombie walking to the start to like keep that distance. And we help them with that. And I'm so happy to say that we also have, again, races in the US, the UK, and also parts of Australia where we can go back to those three people per square meter. We had a 10K race last weekend, which was a mix of a hybrid between social distance and non-social distance which was part of the test that was run by the government. And they luckily go back to those rules before COVID. And people luckily react the same way to it. So when we say here, three people per square meter was safe before COVID, we now have proof or we now have evidence that this will still work post-COVID and will get people the environment that they'll feel safe and that they'll react the way we knew them before.

Panos: 45:06

So, by safe, you mean the Reunion 10K or something, right? The test event, I think that's what it was called, that the government put together in the UK. Are you saying that even when, nowadays, you start people with the three people per square meter density, this event still ended up being safe from a COVID transmission point of view, or from, simply, like people keeping safe and comfortable general point of view?

Marcel: 45:36

From a COVID transmission point of view. There will be a report on this. This is something for the medical side to release but the indications are all quite positive. And the team of the London Marathon, and who were behind those test events, they did a fabulous job of putting all of this together. But here the density aspect - hopefully, we can return to something like this post-COVID - makes a difference for, first of all, how safe they are and how safe they feel. And I just want to give you two examples of this. If I put like, four or five people per square meter and I give one of them a push, or one of them loses their balance, they will all fall. And if my whole start corral falls because I packed them too tightly-- and I can invite everybody to look something like this up on YouTube to look what this looks like at the concert where we can learn from or a gathering to watch football publicly - this is not something that you want to have in your start corral. So three people per square meter is something that means nobody falls and gets crushed because the guy next to me falls and I have enough space to make the step to catch myself before I fall into the next person. And that's a reality that we have now and we'll also have after whatever the reality looks like post-COVID. There might be, sometimes, moments where I need to work with my crowd. I give an example and that might be a delayed start due to something that I need to figure out on the course. I don't want to mention the word terror here. It could also be a water pipe breaking somewhere - that was an example to orientate on - or something that forced me to delay the start just to get something off the road somewhere. And we all know that, let's say, if I go to a library here at my university, I know what the library feels like, how much space I would have at the library left and right of me in order to feel comfortable, take a book out and like read in it, or in the subway, like on the train. I accept an entirely different close contact with people that are packed within one carriage in the subway. So there are two different scenarios in which I accept the different densities. So if somebody comes that close to me in the library, or if he just stood next to me in the subway, it would feel uncomfortable. It would affect my sense of safety and the same is true in a start corral. So if I ask people, we need to delay the start by five minutes, and it may even be raining, and they might not know what's going on, if they have a space that they feel safe in - and that is what we found out, like three people per square meter - they are more cooperative than if somebody is breathing in their neck and I'm asking them to endure this for more 10 minutes and I can't even share with them fully what's going on. And in order to keep them physically safe, and keep them safe in order to cooperate and feel safe, that's the value. And I'm happy to share that we saw races with three people per square meter already, like, not too long ago, just days ago, and I'm really hoping we will return to this reality.

Panos: 48:50

Yeah. Well, so does everyone, I think, listening in. Well, moving on to rule four - I think we shouldn't dwell too much on that because it's something that we've touched on already - which is stick to wave starts. Wave starts help definitely. So rule five which is - at least to me, it sounds quite specific and a little bit counterintuitive - waves should get smaller towards the back of the pack. So what is sort of like the science behind that? Why would you have slower waves at the back than at the front?

Marcel: 49:29

So in an ideal world, I wouldn't need waves because everybody is ordered perfectly by pace. And if everybody's ordered perfectly by pace like in a, let's say, a small time-trial at the Tour de France, maybe, nobody should ever overtake the next one because they're ordered by pace and they're getting on the course with some distance. So no single overtaking. But that's not the reality. And because I cannot order them by pace, I should stretch them out in individual waves and not just ordering them in pens and corrals. It makes sense to put some minutes in between. If I do have the time, like three closer time, I should put some minutes in between. And that means I understand and accept that I cannot order them perfectly. And that's where waves add to this effect. So they're basically substituting the order. And, inevitably, the first runner of the second wave will, at one point, catch the last runner of the first wave and, then, they start mixing. So I delayed the point when they start to mix. I delayed this point a bit. That means, overall, there will be less overtakes on the entire course if we let them do this safe ordering process from the beginning. That's one point. That's by waves unless you have the perfect order which I would love to see the data if you've achieved that. And we are working on trying to get a properly ordered race. But unless you can achieve that, waves really help. And that brings us to this rule number five, "Waves to the back should get smaller." The reason for that is, in the front, I do have fast runners and they normally stretch out better because there are different people with different abilities. If I like, let's say, have a half marathon, it could be that if you run sub-90 minutes, you're still in the first 5% of the overall race. So most races go to about 3 hours 15 minutes for a half marathon - that's where the majority of the race is. So I don't need to focus too much on the guys on the front. First of all, they know their predicted finishing time very well down to the second, like, what their ambition is today. And that changes entirely to the guys in the back. Those men and women that are running there, they don't know that time exactly. They sometimes round it up to the next full 30 minutes. And I need to counterbalance that. I need to take them apart and put them on waves. They also cling together. And they sometimes run in groups. They are much harder to deal with because I have more people around my 3-5 hour mark, and I need to spread them out more which, again, I need to do it at the start otherwise they might stick together more on the course. And I know the reality is completely the other way around for big races where it's hard to put a handle on them. Those are exactly the men and women that I should put into smaller waves. And we mentioned that multiple times now, order is scientifically the best way to do it. And reducing the tap at the start - smaller waves to the back, bigger waves to the front. That will solve the problem on the course. They will order themselves on the course and there's a space to do that. But the focus should be on those guys on the back. And they will appreciate it if I improve the running experience for sure because to face it, they are also our main audience. Kipchoge is great. I love the men. Our main audiences are the thousands and tens of thousands in the back of the race where, sometimes, the atmosphere is much better. And you help them if you allow smaller waves.

Panos: 53:37

Perfect. So let me just summarize for everyone the five rules for efficient race starts. And again, hopefully, we'll get this out into a document for everyone with a little bit more detail. So rule number one, order your field by pace. Rule number two, make sure your start line or somewhere along your start line, there is a kind of funnel that is at least 30% narrower than the narrowest point on the course. Rule number three, keep it to a maximum of three people per square meter at the start pen for just a safe and comfortable race start for everybody. And this doesn't assume social distancing so you may want to adjust that. Rule number four, do wave starts. And then rule number five, try to keep the waves at the back of the race smaller than the waves at the front of the race. Perfect. So let me put to you a couple of questions we've had in our race directors group on Facebook on kind of like crowd density and crowd dynamic. So some people seem to do what they call open starts. So, basically, it's a start procedure where, basically, you keep your startline open for like, 3-4 hours, or whatever. And then people show up and whenever they show up, you sort of, like, roughly make sure that they're distanced, and then you let them go. So you would tell people, "You're on the 9.00am wave" and "You're on the 9.10am wave" or whatever. Logistically, maybe it's easier. Generally, it's quite efficient to do these open starts. And other people are also saying that, "It's also quite efficient to be doing rolling starts" which I guess is what you call like the zombie walk before. Do we have any like data or insights into whether open starts or rolling starts work well for start lines?

Marcel: 55:43

Yeah. We have loads of data now on rolling starts and that they do work. And they also do work efficiently. With open starts, yes, we also saw that working. However, it is less efficient because there are more degrees of freedom that I give to the runner, basically. So whenever I give people degrees of freedom, I need to cater to both options, basically. So to keep my race efficient - from a course perspective depending on the restrictions that I have, and what I need to prove to my individual authorities - I might need to put a bit more control on it. And that brings us back to the point of order. Order always helps. And if I give people a start time, even if it's a rough one, even if it's a very loose one, like show up within this half an hour window and, then, I give the next group of people another half an hour window, even that helps. So any degree of order here prevents unforeseen surprises. And I need to plan for everybody to just freely do what they think is right because then I can be surprised. Maybe, for some reason, some unforeseen train may come at the same time after the morning news, or the morning breakfast, or whatnot. Yeah, both can work. The safer and more efficient one is the rolling start and giving at least rough time windows. And that's a lesson that we learned before from airports and from football stadia who were luckily able to open much earlier before road racing events. And we saw the difference and we saw the data behind it if people have an arrival window.

Panos: 57:31

Another question we get is, nowadays, when local authorities demand races to adhere to some kind of social distancing pattern, or like to put some measures in place, that has repercussions for the maximum number of participants that a race can have - if you have that, for instance, and also how long you can be on the course, it sort of limits you overall - is there a quick, sort of, like, rule of thumb or quick calculation that people can put together to deduce how they can think of the maximum safe number of participants at these times where we have COVID, and distancing, and other effects?

Marcel: 58:12

There is a quick rule that can be used in all the races over the last year - and you're right, we were quite busy - on the course and post-finish. As long as they keep moving post-finish, they all fulfill any social distance requirement. We have seen different ones like how many square meters everybody needs, or how much distance they need to keep - you mentioned 1-2 meters and more - on the course and post-finish. That is not the first thing people need to worry about if they are organizing a road race - it's the start. And just by giving this clarity and this reassurance, that breaks down a massive problem to one that, at least, focuses on one point. And at the start, people aren't moving that much yet. So if you can figure out how many people you can fit safely in your start, whatever that means in your individual situation, or how many people you are allowed to - maybe the government helps you with that, like they give you a facility, sometimes they give a number that they see fit there, and the course with it - that's the reassurance that we can give. And there's also a lot of research data that we can share. If you can figure out your start, the rest will likely fall into place, which then can also be proven by the first point where we started. And we saw very creative examples here where organizers said, "Well one start area doesn't cut it." So we had three start areas and they roll together into one course which gave them three times the capacity and we helped them to figure out to prove what I just said, like the course is still not the problem. You need to have increased start width in this start area even if it means changing the direction of the course because their finish is bigger than their start, and they need the start space. So they basically ran the same course in the other direction to solve that problem. And, then, course and finish is still a challenge but it fell into place. And it's much more forgiving in our particular industry, which is very different from festivals, and so on. So to start earlier, that's, that's, it's open.

Panos: 1:00:24

Yeah, so it's interesting. So, basically, you're saying that if you want to work out the maximum number of participants that's safe for your race to accommodate even with distancing rules and everything, you can reduce that whole problem about what's happening in the race and the finish line and everything as long as people keep moving, and just thinking about how many people you can start safely at the start, and how many people you can safely accommodate at the start. If you work out that problem - which you can, I guess, work out - from just the geometry of the thing, and how long your start line is, and how much time you have to start people off, if you work out the start where everyone is also static, which is a little bit easier, then everything else takes care of itself downstream.

Marcel: 1:01:11

I couldn't say it better because you basically break down a whole operation to at least one picture. You said it is a static one. It isn't like everybody moving at an individual pace. It simplifies it a bit. Like, as I said, a three-digit number of races all fell into place from there if you can solve that one aspect. And we can prove, then, what that means for the course so that you can present it to authorities or internally. Like, once that stuff is figured out, we can look at the next thing but I am quite sure that will be okay.

Panos: 1:01:41

Right. So we mentioned earlier at the top of the show the work you do for people through Start Right. We've also shared some rules that anyone can use. In terms of Start Right, how can people get in touch with you if they really want to take their analysis of the crowd dynamics in the race a step further? Is there a way to contact you?

Marcel: 1:02:05

Yeah. So you can google Start Right. Or you can google my name or start-right.run. It brings you directly to the web page that gives you more background information and they can also reach out and get that support. Our idea is to really hit every size of the race. And, maybe, you find enough in those five rules. I'm like, again, super happy to share this with you and especially with your audience while on your platform. Maybe, that is what helps to support you in the right direction. And if your race or your problem is too complex that those five rules are not enough, then you can get in contact and we can solve that then. Because a big race can by now only be taken apart by big data by the right algorithm that exceeds what we can do. With all brains, we can bring the logic but then, at one point, the numbers need to be run. And what we offer is support to your next race based on a flat rate. As a university, our mission is to, like, help the entire industry by bringing those lessons forward.

Panos: 1:03:20

Perfect. Well, that's been really helpful, I think, for our listeners in terms of both how you can manage an efficient start line when things go back to normal, and also some special precautions that people can take during these very weird times we're going through. I'd like to thank you very, very much, Marcel, for the time you took to share all of this with us. There are the contact details there for people who want to get in touch through Start Right. You have also a very public profile at the Manchester Metropolitan University. Thank you very much for coming on the podcast today. I really appreciate it.

Marcel: 1:03:57

It was an absolute pleasure. Thanks for inviting me.

Panos: 1:03:59

And thank you very much also to everyone listening in and we will see everyone on the next episode. I hope you enjoyed this episode on managing participant crowds with Manchester Metropolitan University crowd scientist, Marcel Altenburg. You can find more resources on anything and everything to do with putting on races on our website RaceDirectorsHQ.com. You can also share your questions about start line procedures, participant social distancing or anything else in our Facebook group, Race Directors Hub. If you enjoyed this episode, don't forget to hit "Follow" on your favorite player and do check out our podcast back-catalogue for more great content like this. Until our next episode, take care and keep putting on amazing races.