I don't understand your question.

I'll elaborate on my earlier point. I bet that in big stations like Metro Center, Gallery Place, and so on, you will walk at least 50 yards to some busy platforms from popular entrance points. If you take a wrong turn or decide to go to the front/rear of the train, you'll go a lot further. The surface is smoother than most well maintained sidewalks, but you'll still get lots of rattling with circa 2007 EZ Wheels that make steering the folded bike in a crowded station a pain. It was much better with larger skate wheels. No comparison, IME. Totally worthwhile despite the occasional heel strike. Skinny 70, 80, 90+ mm wheels would be a welcome experiment IMO. (perhaps it has already been done but created other problems)

During doctor visits at GWU Hospital and NIH, the distances were much further than that.

For a short period of time, ~25 pounds isn't that much weight; but it gets old really quick since one is typically carrying other stuff too.