In what appears to the most magnanimous of gestures, Bentley Systems is making LEGION Simulator, perhaps the most sophisticated of all the crowd simulation applications, and OpenBuildings Station Designer, available at no monthly cost until September 30. In a world that is trying to reopen while still in the throes of a pandemic, Bentley is hoping that at least buildings, subways and airports will be safer for the availability of its software.
Usable for hospital shift changes, office workers in high rises massing at or in elevators, and riot control, crowd simulation seems to address both of the big crises facing the nation, COVID-19 and the Black Lives Matter (BLM) protests. However, coupling LEGION with OpenBuildings Station Designer shows Bentley’s focus on people movement in subways and train stations, where rush hours will reemerge as shelter-in-place orders are lifted and as people, masked or otherwise, will invariably end up closer to each other than they should be.
Planners use video to observe massing during rush hours and have, no doubt, learned about crowd behavior during normal conditions. However, planning for physical distancing rules that may have added extra gates, widened some passages while closing others, created new one-way lanes, etc., will boggle the mind and test the imagination. Should that be insufficient to plan for reopening, we have crowd simulation software like LEGION.
With people movement simulation, a building manager, hospital director, or transit official can see the effect that signage, increasing crowds and distancing will have. Will more turnstiles at exits be the answer? Or sending fewer trains to the station? Will staggering shifts, and by how much, cause the least crowded elevators?
LEGION Simulator lists its abilities to model and analyze social distancing plans, egress/ingress and evacuation plans.
“We are going through extraordinary times and change will be a constant reality in the months and years ahead,” said Ken Adamson, vice president of Design Integration for Bentley. “OpenBuildings Station Designer and LEGION Simulator enable planners, architects, engineers and operators to apply digital twin approaches to solve today’s design and operation challenges more quickly, efficiently and safely across rail and metro stations, airports, and other public buildings and amenities.”
A New Ball Game
Modeling people movement is literally a whole new ball game. The crowds at sporting events are planned for. AECOM, one of the biggest builders of sports stadiums, maintains a team of experts dedicated to pedestrian modeling. When Bentley acquired UK-based LEGION in 2018, AECOM was there to support it.
“The urban space team of AECOM, based in the UK, has been using LEGION software for various crowd modeling projects for more than 10 years, said Samya Ghosh, then regional director (EMEA) for transportation projects in Europe, Middle East India, and Africa for AECOM. “The crowd modeling is primarily undertaken to provide an evidence base for wider evaluation of existing and proposed rail infrastructure, public realm, sports venue and major event planning, and design or refurbishment of large institutions.”
Modeling People—It’s Complicated
If you considered FEA or CFD the height of sophistication, welcome to much greater heights. Both finite element analysis (FEA) and computational fluid dynamics (CFD) model systems with a continuum, rather than discrete, behavior. Particles, like grains of sand or cars on the highway, can seem erratic by comparison. Systems can have combination, particles in a fluid, like blood cells (particles) in plasma (fluid) in your veins or logs in a river.
If that’s not complicated enough, let’s make the particles behave like people. Now, everything changes. We are dealing with particles that react to stimuli, like signs, and follow those ahead of them in normal times and panic and stampede over them in the worst of times. They are prone to patterned social and cultural behavior, with social distancing (it varies with culture) even before COVID-19. That’s a lot to put into software and it’s hard to imagine that it would fit in any one platform. The product page of LEGION does claim that it will “mimic all aspects of an individual’s movement including personal preferences, surrounding awareness, spatial restrictions, and perception of behaviors.”