This trip takes me around 2 hours and people think i am crazy for doing this.. but those same individuals will spend an hour commuting and then go to the gym for an hour?
Cycling isnt suited to a few miles.. I have never been "athletic" and can do a 50KM ride with a bit of training.
If the ground is fairly flat i'd say 10 miles is reasonable.
These distances can be easily covered on foot or bike with minimal change in infrastructure.
[0] https://www.bikeleague.org/content/national-household-travel...
https://nhts.ornl.gov/vehicle-trips
For vehicle trips:
21.4% of trips are 1 mile or less.
35.2% of trips are 2 miles or less.
45.6% of trips are 3 miles or less.
This seems likely to work better in areas that aren't as geographically constrained. Seattle, for example, has far too much water around it and industrial areas near that. It'd be a good one-shot conversion though.