These numbers are boardings only - TTC numbers are boardings and alightings. So to compare them, double GO's numbers. Oakville GO is comparable to Museum station, for example. Union is equivalent to, well, Union.
The TTC's system is more confusing to picture, they do count boardings and alightings for individual station counts, but full line counts take the sum of all station counts and divide that by 2 (instead of counting all the boardings). Actual ridership may be higher due to fare evasion.
GO's system makes me want to rip my hair out, and the biggest issue is Union Station. The numbers they are reporting are likely the number of riders that are using only the outbound stations. UPX's numbers are fairly accurate, but every other line can be effectively doubled to get your true daily ridership. (it's going to be a bit less because many people don't commute into Union Station. Until we get an idea of what Metrolinx's methodology for this mess is, our best guess is to say that the true daily ridership of each line is as follows:
Kitchener — 26.2 K PPD
Barrie — 18.2 K PPD
Richmond Hill — 12.4 K PPD (this one really surprises me, and this one is more accurate than the rest because almost everyone on this line goes to Union Station)
Stouffville — 19.2 K PPD (Another one that surprises me, this is more than the barrie line while this line is having lots of construction)
Milton — 32.4 K PPD (Another line where the majority of people are going to Union, even with 1.1K fewer riders due to Kipling Station (Worst case scenario), this line's ridership is still huge).
LSW — 59.8 K PPD (lower ridership a result of people riding through? Given the new fares, this one really has me stumped)
LSE — 43.4 K PPD (See LSW comments)
Also, some more statistics from ION:
Press Release:
http://bit.ly/2XxwzLu
Friday: 21,500
Saturday: 29,500
Sunday: 22,000
Also, detailed GRT statistics thanks to
Cory Albrecht
docs.google.com