Is Phoenix Light Rail Fudging Its Charts to Look Better?

I bring your attention back to this chart from this post the other day about light rail killing transit growth.

ridership_140903_annotated

I have no evidence that this chart was deliberately manipulated, but somehow the light rail ridership bar for 2014 got exaggerated.  It certainly seems suspicious.  Light rail ridership went up from 2013 to 2014 by only about 45,000, or 0.3%.  This is negligible  We should not even see the bar move.  Note the total ridership in 2011 and 2010 when ridership fell by 86,000 but the bar lengths are almost indistinguishable.  The rail ridership looks to my eye like the bar is 7-9% longer, not 0.3% longer.  In fact, the bar for 2014 clearly goes past the halfway point between 10 and 20, despite the fact that 14.3 should be less than halfway.  In fact, the 2014 rail increase of 45,000 is graphed as visually larger than the 1.3 million decrease in busses.

  • Ben

    The distance between 0 and 50 million is 319 pixels, so it's 156740 ridership per pixel. With that conversion, the bar widths indicate

    2014: 15.8M-16.1M light rail ridership [14.3M claimed]
    2013: 14.4M-14.7M light rail ridership [14.3M claimed]
    2012: 13.5M-13.8M light rail ridership [13.5M claimed]
    2011: 12.5M-13.0M light rail ridership [12.8M claimed]
    2010: 12.2M-12.5M light rail ridership [12.1M claimed]
    2009: 6.1M-6.4M light rail ridership [5.6M claimed]

    So yes, the bar for 2014 is definitely too long. 2009, 2010, and 2013 are also a little too long, but perhaps within the realm of layout inaccuracy. I wonder how such a chart could have been generated -- it's not like computers usually make mistakes like this.

  • Bob

    Agree with Ben

  • Eric Hammer

    Judging by how hard the graph is to read in general, I suspect it was not entirely accidental. I have not done pixel analysis, but it is not at all clear that adding together the bus bars and the train bars yields the total bars. And why have 3 bars instead of stacking the rail and bus bars? For that matter, why start with all bus bars then add both trains AND a totals bars? With the way things are stacked and ordered it makes it really hard at a glance to tell what is going on, rather defeating the purpose of a graph. Unless of course your purpose is to obscure but hint at what you want to be true. (It is also odd that the magnitude goes horizontally while the years are vertical.)

    Maybe I am just used to seeing such types of graphs presented a certain way, but I used to prepare graphs of similar information and they all worked a lot better than that.