I don't.
Twenty years ago, I did a six week project in Washington DC for my company. They set several of us up in a rental house in Georgetown, but we had to figure out how to get ourselves to the jobsite in Dupont Circle on our own. Some guys bought bicycles, but I just walked.
It was about five miles, and as I recall, it took me a little over an hour to make the hike. I did the same thing every evening after work. Double the distance would have taken me a bit over two hours each way, which is about how far this guy's been hiking to work all these years.
It can be done.
So the article is misleading due to the tile, which is why I didn’t buy it since he doesn’t walk the entire 21 miles.