Crowd Counting for Event & Crowd Safety

Author / Mark Breen
02 Feb ‘17
Counting the number of people in crowds is something we, as event organisers, often have to do on a very large scale. The practice of doing so is quite topical at the minute, with the arguments over the size of the crowd at the recent inauguration of Donald Trump. There's more on that particular one throughout this mailer. 

The challenge

The question of how many people attended an event is a confusing and frustrating one. We tend to hear conflicting reports on attendance figures, especially for things like protests, large city-wide events, parades etc. 

Confusing & frustrating as it may be, there's simple logic as to why there tends to be differing figures reported. Consider this:

  • The organisers want the event to seem successful so it's in their interest to report a high figure.
  • A police force may have a vested interest in downplaying the size of the crowd so as to justify their staffing levels if, for instance, they were under pressure finding staff to work it.
  • The media may have a vested interest in a figure being low or high depending on the subject matter. For instance, if it's a protest march by a left-wing group then a right-wing media organisation may seek to report a low figure. 
  • A venue owner may need to be very careful about what figures are reported so they're not seen to have had more people than they should have had inside their venue. 

Those are examples. Once you realise and accept people reporting attendance figures have different motivations, then it makes more sense. It can STILL be frustrating but it makes more sense. 

The key points

There are 3 main elements to this:

  • The people quoting the crowd size figure usually have a vested interest, be they the organisers, the police force, detractors etc. 
  • It IS difficult to know how to accurately estimate the crowd size unless you've been trained to do so.
  • There ARE ways to estimate crowd sizes with a decent degree of accuracy. They require and understanding of crowds, density, area etc. and the use of some simple tools.

The reality is that professionals that know how to count crowds are rarely engaged to actually do that. That said, recently Prof. Keith Still and Marcel Altenburg from Manchester Metropolitan University were brought in by the New York Times to observe the crowd at Trump's inauguration and estimate the crowd size as things progressed. Some of the articles below elaborate on that work. While it's a recent example, it is one of those rare occasions.

The bottom line

Don't trust figures unless they're been assessed independently by people with no skin in the game. Nine times out of ten the reported figures will be inaccurate.  

Further reading

Check out:

4 Useful Tools for Counting Crowds

Crowd Counting Resources

Crowd Counting with Professor Keith Still | Inside the Box