[crazytony]

Generous like this table from your article?

                   cost(2013$) riders(thousand)   cost/rider
  O-Train (lrt) 	27M$       14                   1901$
  

...

If you don't understand why your table is extremely flawed then you should pull this article. If you do understand then you are being disingenuous not generous.

[ant6n]

I was generous in that I ignored the worse performing data-points according to the heuristic I picked. I wrote that the projected REM ridership doesn't look outrageous, just optimistic, and suggested that placing Montreal at the 80% instead of the 90% percentile may be more realistic. Did you even read the text?

Regarding your unrelated attack, how is it possibly flawed to ask for a transit project to bring a certain number of riders relative to its cost, no matter the mode? This is a standard way to get an idea of the effectiveness of a transit project.

These are back of the envelope calculations that are pretty fuzzy (this is not programming or math, folks), but they are incredibly useful and very easily reveal fishy projects. I wish the public would be more vigilant, even doing very simple calculations like this is helpful -- then maybe in North America we could waste less money on stupid prestige projects, and spend more money on actually building useful transit.

I find your suggestion that I should pull my article extremely unhelpful. We here in Montreal are currently being duped by a semi-private entity to waste a shit-ton of public money on a deeply flawed transit project, while useful projects sit waiting. I want to write about that because I think people should understand how its flawed. If you don't give a fuck about Montreal or Quebec, fine. But don't try to shut me up based on nitpicks that miss the point. If you want to tear down a bunch of bullshit, maybe do something useful and go write about the REM project yourself.

[Programmatic]

He was pointing out that you mixed your units in your analysis. You divided annual cost by daily ridership for the cost instead of multiplying the daily ridership for annual ridership. I think he was short in how he pointed this out to you. That being said, as the one presenting the data I believe it's in your interests to ensure that what you wrote is accurate. When someone shows inaccuracies, I think it's disingenuous to continue to use data that has been shown to be flawed. That was more tersely expressed as "you should take it down."

I would recommend changing your units in your site to either be all daily, or all annual. This means that you could meaningfully present and compare percentages of ridership, like I did for ATL above.

Getting back to the numbers at hand, YUL has 82% O&D[0], meaning that for 15M passengers there will be (15m * .82 / 365) -> 33,298 daily users. 30% daily ridership does seem like a steep target to hit. If you get the O&D numbers for all of the airports and compare daily values, you may still be able to express you idea and make a case without people being distracted by inconsistencies.

Another factor to add, eyeballing your graph, would be the correlation of metro ridership to the percentage of airport passengers opting into the metro. The numbers for the southern US would probably be explained by a poorer metro compared to SF and the northeast.

You put yourself out there, and you obviously are passionate about your subject, but please take a step back to look at the suggestions and how they will improve your case or show you new insights.

[0] http://www.admtl.com/sites/default/files/RA2015_A.pdf "The percentage of connecting or transit traffic held steady at about 18%, i.e., nearly one in five passengers, or 2.8 million people for the year, had an airport of origin or destination other than YUL."

[ant6n]

I couldn't get the O/D data, I tried to find it for Atlanta. Didn't find it, gave up, and posted the graph with numbers that I had. Note the ridership numbers are for different years, so the only reliable matching number I could get was total passengers. It's true that will punish hubs, but I think think as a back-of-the-envelope calculation it's okay. The focus isn't on Atlanta, it's on Montreal, Toronto, Vancouver, New York, Boston - and that's where I see the comparison. Even if Atlanta was three times 'better', it would still be on the right of the graph.

The cost is not 'annual', it's the capital cost expressed in 2003 dollars, that is, adjusted for inflation. I would've never guessed crazytony's issue was with that, because it was just a flat attack without any substance. Giving cost in M, ridership in K, and cost/rider in $ seems fine to me. The numbers are meant to be compared across different projects, and are easily verified to be calculated correctly.

You can't just divide annual ridership numbers by numbers of days in a year, because ridership numbers are given for weekdays, and weekends have wildly different numbers. The ratio can be anywhere from 260 to 365, depending on the actual line... or airport.

I left the annual airport passengers compared to the daily ridership intentionally, because those are not numbers that can be directly compared for various reasons. I intentionally wanted to create an obscure ratio because I wanted to compare across different airports, not give any estimatable number for any particular airport.

In any case, this particular graph is not the overall point of the article, I'm merely trying to get an idea whether they are being crazy with their predictions.