Sidewalk rant

I took it into my head this afternoon to try to walk all the way home from my doctor’s office, it being a beautiful day. I was pretty sure the walk was less than 4 miles, and I got out of my appointment just before 4pm, and I was wearing sturdy shoes. So I set out.
Problem: once you get past the Grosvenor Metro station on southbound Rockville Pike, the sidewalk ends. Sort of. Not definitively. There are bits of sidewalk, enough that I tried going a couple of different ways before I gave up and took the path of least resistance, which was Beach Drive to the Rock Creek trail. I asked a fellow walker if she knew where it let out, and she told me that it hits Cedar Lane. I expressed my dismay that I had been unable to walk to Medical Center from Grosvenor along Rockville Pike, and she expressed sympathetic outrage. “It’s like we’re not supposed to be walking.” So I found Cedar Lane, walked up hill and down, past Stone Ridge to Rockville Pike.
It was a lovely walk, but it was 5.25 miles instead of 3.8 (thanks to the Gmap Pedometer), and I didn’t have any water and I felt a bit panicky not always knowing where I was or how much longer it would take me to get home.
There should be sidewalks. Or there should be big giant signs saying that the sidewalk is ending and to go another way. Or preferably, a sign at the Grosvenor Metro pedestrian access point that says “no thru pedestrians to Medical Center”.