9/12 March Crowd Size

UPDATE 2:

According to gusopo13, these estimates also appear to be backed up by the numbers riding Metro (allegedly, still trying to find the formal press release).

For a fair comparison, we looked at the Saturday after Labor Day in 2008, which is when September 12 fell in 2009. On September 12, 2009, 437,624 rode metro rail. By comparison, on the Saturday after Labor Day in 2008, 202,528 rode. The difference is 235,096.

I would point out that these are Metro rail ridership numbers. Presumably, most of those who took Metro rail down to the event also took it home. Thus, this actually only accounts for perhaps 117,000 - but it still surpasses the 100,000 mark which discredits the media's (and fire department) numbers AND does not consider anyone arriving at the event by means other than rail on the day of the event. Those in local hotels, riding in on busses, driving personal cars, etc. would all add to this number.

This is where gusopo13's article also provides some insight. If you apply the ratio between increased rail ridership and estimated crowd attendance for Obama's inauguration to the 9/12 crowd, it is reasonable to estimate a crowd size of approximately 300,000 to 450,000. Once again, regardless of the exact number, it is very clear the that it was hundreds of thousands.

UPDATE:

Charlie Martin provided his own estimate and comes to a 850,000 number. While I think his is at least an honest effort to come up with a count, I think it is an extreme upper bound and I'll stick with mine. My full response to his analysis is below:

At best I’d call it an upper bound. I am actually a traffic engineer and I know something about walking speeds because I used to time traffic signals (including the walk interval). The standard design speed is 4 ft/sec, which comes out to 2.7 mph. Even at the end of the march, the crowd was moving below this speed – or at best at the speed; which is not surprising since there were a range of ages, etc. I’ll call the speed at the end 2.5 mph. However, at the start of the march, the crowd was much denser but also MUCH slower (also not surprising with anyone familiar with crowd dynamics). At best, I’d call it 1.2mph.

The estimates of the street being 100 feet wide is probably realistic – at least as far as usable width is concerned (i.e., there were periodic barriers and other things in the street that decreased the width a bit.) There was also at least one slow moving float in the march that would have lowered the count a bit. The length would be 5700 feet, so the area is 570,000 sq ft, slightly less than his number, but within rounding errors. Crowd density where he had numbers we probably a little below standing crowd numbers – So once again, his number of 100,000 to fill Penn on the march is on the high side but still reasonable. The catch is he then uses a fast walking speed with a dense crowd rather than a very slow speed, which was occurring at the count site. That would cut his number by 1/2 to 1/3rd. Or down to 300,000 to 400,000 as actually marching past the point. This is very different than the 1.5 mil cited.

Of course the real way to measure moving people on an averaged type basis is based on headway, i.e., how much time elapses between one person and the next. At the extreme, people do not walk closer than at about one second headways – because reaction times are about a second and people don’t want to bump into each other. Perfect symmetry would allow perhaps 33 people to be marching across the street (i.e., 100 ft wide / 3 feet per person). This would produce an upper bound estimate of about 3600 pp/hr * 33ppl wide or just over 100,000 ppl per hour in a very densely packed crowd. This means a maximum of about 350,000 over the three hour period. This would line up with my revisions above and also is very similar to a few other analyses I performed at http://www.political-gumbo.com

I will concede that there were probably many that came to the main event, but not the march, but I still don’t think it was anywhere near a million. Also, based on my observations and the pics from Obama’s inauguration, I don’t think we were anywhere close to those numbers. We were probably more densely packed, but we certainly did not have the depth of the crowd (as near as I could tell, the crowd only went back to 1/3rd of the Mall and we were not allowed on the back part where another event was scheduled.

I would have liked to have seen more people there, but I also believe that we need to be as objective and truthful when we report our numbers. I understand that others are not – but that is what makes us different.

--------------

Many people have asked about the crowd size on Saturday 9/12. I have heard numbers ranging from thousands to 2 million. So what is the real number:

• The headlines of the New York Times and AP said thousands
  
• Most of the mainstream press, including Fox News, and the actual stories under the NYT and AP headlines, stated tens of thousands
  
• Rumors on-site that there was an actual count of roughly 450,000 that marched past Penn and 11th.
• Statements from the stage or other "official leaders" that there were "official" reports (e.g., from the park service and/or similar) that there were 1.1 million and then 1.5 million - but this was odd since these groups have stopped providing official counts.
• The Daily Mail initially reported "up to two million", but since reduced it to "as many as a million"

Quite the range. It actually got me to thinking... The technology HAS to exist to take a high resolution arial photograph and process to the image to get an exact count (within some reasonable margin of error). It is sad that none of the powers that be are wiling to pay to have this done. This is a discredit to both the media and to the organizations involved (e.g., FreedomWorks). I firmly believe that the people there wanted a true and accurate count and it should be done.

What I can say from a personal perspective is that the crowd seemed to me to be roughly the same size of the "Stand in the Gap" crowd in 1997. I was at that event as well. However, that event took place at the Washington Monument (at the other end of the Mall) and the arrangement of space and speakers makes it somewhat difficult to exactly compare crowd sizes. For example, the Stand in the Gap event was focused primarily down the Mall and the vast majority of people were on the Mall. The 9/12 March was focused on the Capitol building and the speaker arrangement resulted in better sound on the sides of the capitol then on the far side of the reflecting pond. As a result, the crowd covered a much broader area then in the case of Stand in the Gap - and as a result, was not as deep (i.e., the crowd was in a wider and shorter space). But in my mind the crowd was in the same order of magnitude.

Unfortunately, there was no official count of Stand in the Gap either. However, shortly before Stand in the Gap was the Million Man March. The Million Man March had an official count by the Park Service of 400,000. The organizers complained that this was inaccurate and that the real number was between 1.5 and 2 million. Boston University then did a study and said there were 837,000 plus or minus 20%; but other academics supported the lower Park Service number. The controversy surrounding this issue resulted in the Park Service stopping it practice of providing crowd size estimates. Whatever the real number, the arial photographs of Stand in the Gap suggest that it likely had a larger attendance, but perhaps only by 20%. And as I stated, my personal opinion was this crowd was in the same ballpark as Stand in the Gap - perhaps a bit smaller - although there are various difficulties in comparing the two crowds. That would put the crowd size at perhaps 400,000, if you stick with the Park Service methodology.

The other thought that I had was "How many professional football stadiums would be filled with this crowd?" While this is obviously an imperfect science, my thought was "multiple, certainly more than one, but almost as certainly less than 10." A typical professional football stadium will seat up to about 100,000 people. So this seat-of-the-pants methodology would also seem to support a number of 400,000.

Finally, I saw a link provided by Michelle Malkin to a USA Today article written for the Obama inauguration that provided an indication of how various crowd sizes would fill up the Mall. Based on my observations, the crowd filled the area to about the 350,000 point at its peak. This is probably the most accurate of the three above methodologies, but what is interesting is that they all produce numbers in the same ballpark; thus I actually have a fair level of confidence in this number at this point.

So, my specific answer is 350,000. However, I believe the precise number is somewhat unimportant - what is important is the truthful and accurate reporting; it is clear to me that the real count is "hundreds of thousands". I do not see how any responsible reporter could suggest that there were only "tens of thousands" at the event - let alone the "thousands" that the NYT and AP had in their headlines. However, what I find equally if not more concerning is the willingness of the event organizers to inflate the numbers. There were not 1.5 million at the event either. If we are going to complain about the media providing inaccurate numbers, we first need to be truthful ourselves. Stating that the Park Service has provided numbers when in all likelihood they didn't - at least not in any official capacity - is inappropriate. In fact, it highlights one of my concerns - that there are many of those in power who will try to use this movement to achieve their own gain, despite the fact that they do not truly share our beliefs. We should demand accountability from FreedomWorks and others on this issue - even more so than from the media. We must remove the log from our own eye first.

Perhaps these people just made a mistake - they heard one person cite a number and then it got mistranslated and misattributed, etc. but if that is the case, they should recognize the problem now and issue a correction and an apology. Being off by 10, 20, even 50% is one thing, but it appears that both the media and FreedomWorks were off by 4-5 fold. That is simply irresponsible reporting.