To Mr. @
downtube42 It isn't an "average" speed if it isn't an average of speeds. If a person hits 48 mph on the one downhill on a ride and says he "averaged" 48 he is ... well, wrong, let's leave it there. As for "instantaneous speed they see most often" then the average speed is a matter of when they look. If I only check my speed when pulling off form a stop ......
As I mentioned, I use "average speed) which is a function of time and distance, not chance or dishonesty, and I note other factors. I also note the feet/mile of altitude gained. Obviously if I am riding a route with three times the hills, I don't expect the same speed ... but see, i am smart enough to understand that extremes... hills wind, rain, bad traffic, ill health or just the "I don't have it today" factor, all affect the average speed.
Also, since I am not competing with anyone, including myself, average speed is just an indicator, as is rides per month, miles per year, etc. it is a measurement, not a judgement. It is just data, and it has different meaning in different contexts.
If I ride off-road on tough terrain I might travel a third of the distance in a given time and still do more peak-effort work. I know that, so I don't freak out if my average is low .... if I get a tailwind both ways on a flat route, I don;'t think i am Superman (but I feel like it.)
When I read about how much some others here ride, i don't feel elevated or diminished. I assume their averages include good and bad days and different routes and all that, and I notice a lot of them include elevation gained, because they track that too, knowing it makes a difference. This isn't a measuring and comparing contest .... it is just some folks who ride bikes sharing anecdotes.
Yes, if I put my bike on the rack and drive a hundred miles of highway to get to a ride and leave the app on, I can get 100 miles at 80 mph added to my ride ... but that isn't really what this is all about, is it? At least for me it is not.
Not aimed at you sir (or madam) but ... some threads are people riding out high speed through a crowded forum yelling, "Strava! Strava!"