I'm not quite right yet (am I ever?), but I felt well enough to get in some walking today. I decided to go ahead and do my scheduled speed workout in the cul de sac across the street from my house. The schedule called for 8 X 400, at my 10K pace, but I know I wasn't ready for that many reps after not walking for a few days. I opted for 4 X 800+ at a fast pace. My son was with me and did a good job of encouraging me to keep going. He was surprised that I can walk faster than he can. Luckily he didn't challenge me to a running race.
I feel OK, my shins were tight while walking and I slowed a little for each lap. The laps were 4:11, 4:21, 4:21 and 4:25. I know it was farther than 800 meters, I definitely walk faster than a 16-min mile. I'm going to have to measure out more specific distances.
NOTE: I've used MapMyWalk for general distances in my neighborhood with good success. The only problem I have is it seems to miss the round end of a cul de sac. On maps they show up as deadends - but I walk the full loop. I haven't figured out how to work around that yet.