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 eventsHow your start line procedure affects everything that happens downstream at your race race courseAlways try to order start waves by pace (faster runners at the front, slower runners at the back), even if you can't do it perfectlyMake your start line 30% narrower than the narrowest point on your course to avoid congestionAim for a max 3 people per sqm in your start pen for a safe, comfortable race startKeep start waves of slower runners at the back smaller than start waves of faster runners at the frontPrefer rolling starts over open starts to eliminate the uncertainty of people arriving at random timesFor socially-distanced races, keep participants sufficiently socially-distanced at the start and they will only spread out further during the courseThanks 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.