Originally Posted by MikeMunson

It probably depends on the individual and their personal activities, and I suspect there is a threshold for each person, where they switch from comparing it to walking/running (if they are familiar at all with walking or running) to comparing it to driving distance. The whole point is that, like everything else, it's relative, so when you throw out a distance, an individual will compare it to whatever is close to that distance and is familiar to them, maybe what they experienced most recently.

For instance, I have regular 40-mile routes I ride out in the National Forest by myself. Sometimes I think I should extend that route a little longer, but I reel myself in when I remember that it puts me 15ish miles from home, and how that would be a long way to have to walk.

But on the other hand, you mentioned 100 miles above, and my first thought went to the day-trip I took on Saturday to go ride some trails. I drove 90 miles on the interstate at 70+ mph...I know I was a long way from home by bike (or if I had car trouble...there weren't any cities nearby). Maybe another day I'd think, my dad's house was 120 miles...that's a not insignificant drive in my truck, I can't imagine doing it by bike. Or if you said 50 miles, my first thought was...well that would put me well into the next state over if I went North.

I notice that when I hit that certain distance threshold, that I stop thinking about walk or riding my bike that distance, I always relate it as a 1-way trip distance, rather than a round trip. That's interesting.