Tuesday I tried a variant of the "light day", walking the same path as my downtown walk, but stopping and turning around at the bottom of the hill by Engineering. That gets me all the elevation change in a shorter time. I turned it around in 19 minutes, which is about what I would have extrapolated (interpolated?) from my downtown times.
Wednesday was too busy at work.
Thursday I walked all the way down to Airport Road for the first time. 34 minutes round trip. It's 2.2 or 2.4 miles, according to slightly different lookups in Google Maps, so that's a pretty good clip. Also kind of tiring in the legs as well as the aerobic system. I felt tired for a good bit of the afternoon. Still, it was exciting to finally get all the way down to the corner -- I've been thinking about that as a goal for years.