Crowd Behavior

Every three years Zürich is hit by Switzerlands biggest event: the Züri Fäscht. Over the course of three days 3 Million people come together to dive into a a large program of concerts, dance parties, and attractive shows.

We developed an App that has been deployed during the event. Offering event information, attractive features such as a friend friender ora trophy collection game, the app was downloaded more than 56.000 times.

We collected GPS positions from 29.000 users during the event.

Based on the collected data, crowd densities have been esimtated and shown in real time to police authorities. Furthermore parameters such as crowd speeds and velocities have been calculated (see Fig. 1).

Live view

During the festival the crowd density has been visualized in real time at the City Police Zurich. Users upload their current position in 2-min intervals. Using a web-based interface a map visualized the mobility of the crowd on a large command&control screen.







Based on the crowd density, the popularity of events at certain times and certain locations can be estimated. The plot visualizes increases and decreases of the audience relative to the observed places (Muensterbruecke,...China Garten).







The users - how to get 'em!

Besides creating awareness through press releases (see below), we are required to offer something beyond "this app is an academic experiment - you are doing good in participating". Expecially as our app puts stress on the battery runtime. To this end, we developed a trophy collection game that is based on the continuous location mechanism. Yet simple, its game mechanics captivated users and we had a story to offer to the press.

Side note: indeed, I designed the trophies, ain't they cool?


Supporting Viral distribution

To support viral distribution, users could share their badges and achieved points on facebook - being as suggestive as possible: "My Trophies (177 points). Where are your's?".

Press releases

To increase potential App users, we developed a communication strategy that resulted in significant traction on "multimodal" media outlets. Opening this channel to potential users, it helped us most to boost AppStore downloads. A selection of numerous press releases is given below.





NZZ 29.06, Tagesanzeiger 08.07

20min 19.06, 20min 08.07, 20min 08.07 Blick 08.07, Tagesanzeiger 29.06 ...


Radio-Interview (I don't remember which one)

Radio Energy ...

SRF Digital


SRF Tagesschau, Tele Top

Tele Zürich Talk Täglich

BBC News



SRF Web 19.06, SRF Web 04.07, PCTipp 04.07

Inside-IT 08.07, OnlinePC 06.07, ...


Preliminary results have been shown to the public at ETH Zürich yearly exhibition - Scientifica 2013 as well as to

Furthermore, we an interdisciplinary audience at




We based parts of the data collection on the coenosense platform developed at our group at the Wearable Computing Lab, ETH Zürich.



[1] Capturing crowd dynamics at large scale events using participatory GPS-localization. U. Blanke., T. Franke, G. Tröster, P. Lukowicz. ISSNIP 2014. Singapore

[2] Crowdsourced Pedestrian Map Construction for Short-Term City-Scale Events. U. Blanke, R. Guldener, S. Feese, G. Tröster. Urban-IOT 2014. Rome, Italy

[3] How to Save Human Lives with Complexity Science. D.Helbing, D. Brockmann, T. Chadefaux, K. Donnay, U. Blanke, O. Woolley-Meza, M.Moussaid, A. Johansson, J. Kraus, S.Schutte and M. Perc Social Science Research Network (preprint)

[4] Participatory Bluetooth Scanning as Urban Crowd Probe. J. Weppner, P. Lukowicz, U. Blanke, and G.Tröster(in preparation)

[5] Crowd-Monitoring am Züri Fäscht. U. Blanke., M. Wirz, and G. Tröster. Electrosuisse. 2013 (German)