Maybe we're looking at two different things, but on their website it shows Macleod Trail/Ring Road intersection as high stress. I see Country Hills town centre as a mix of high and low stress, but the Bow River pathway as low stress.
This is where I'm looking
https://bna.peopleforbikes.org/#/places/4f374ae8-09cf-4f81-aa1e-902cc879da7d/
I agree the methodology isn't perfect, I would have three categories: Low stress for dedicated pathways or protected cycle lanes, medium stress for roads at 40km/h and high stress for those above that. Cities with boatloads of dedicate pathways like Calgary would do even better.
If you click the layers tab on your link, you can see the 'Census Blocks With Access' layer, which is the map I saw with this link:
https://cityratings.peopleforbikes.org/cities/calgary-ab
You can also look with different layers at the detail going into the calculations, and it's just really not good all the way down. The destinations -- the 'colleges' they measure access to don't include the University of Calgary, but do include both the Alberta Bible College and the MC College (a hair and makeup school). The links - they track four types of bike infrastructure, but they aren't consistent with them; cycle tracks are sometimes Off-Street Paths and sometimes Protected Lanes. There are entirely imaginary cycle facilities there, like an Off-Street Path in the alleys south of 17th Ave, and another one in the back lane north of 10th Ave. Meanwhile, the cycle lanes on 14th/15th -- not great, but definitely Conventional Lanes like 26th Ave or 11 St between 12th Ave and the Bow -- aren't included, and this is March 2022 updated information.
It's not that the methodology is imperfect; it's fundamentally using incorrect inputs; no matter how good the methodology, you can't produce correct results. This is like a bunch of 'big data' approaches, which rather than doing the hard work of correct analysis, just dump in a bunch of free whatever and allow you to draw incorrect conclusions about dozens of worldwide cities at the same time. I have no faith that Calgary is the unique case they made a bunch of mistakes with, but that every other city is correct. The worst city they score in Canada is Victoria, which is also the clear leader in cycle commuting. (As of the 2016 Census Victoria has more cycle commuters than Calgary, despite being 1/4 our size.)
On the methodology side, I agree with you -- the two levels of stress isn't sufficient to really describe what's out there, and that's a big problem. There's actually a
key piece of the literature based on a study in Calgary - a survey of cyclists produced roughly this distribution of values of time for riding on different types of facilities:
This suggests several levels of facility, not far off your ideas; low-stress are protected facilities (probably including cycle tracks, which this study predates); medium stress are lower-speed, lower-volume residential roads and perhaps busier roads with painted lanes; high stress are above 40 km/h roads, and the other missing category - inaccessible including at least all freeways, and plausibly multi-lane roadways with speed limits over 70 km/h.