Oh I think that standard is great. I just thought there might be an easier way that clicking every schedule to see which had 15-min midday headways. But looks like you're done anyways.

And besides, if the goal is to know which routes effectively serve schedule-less riders, public perception probably plays a valuable role too. It's a rare person who's ever going to look at the schedules, 0 to 200. The only routes I would personally expect to hop on schedule-less would be Colfax, Broadway, Federal... the ones you captured. Even if by some fluke Wadsworth or 104th had 15-minute service, presumably because it was needed, what random joe schmoe would know that or expect it? Not I. Of course, I would stroll down to the 3 or the 38, maybe, expecting frequent service... and apparently I'd be disappointed, haha. Just thinking out loud. I've always likes the idea of separate branding of high frequency routes. But from what you're finding, there are so few, RTD might be better off not having it. The only surprised on your map (as compared to "common sense") are what's missing, not what's higher frequency than expected. Hmm.