Last November, I filmed in the Washington Metro a little. It was the day after Thanksgiving, meaning it was Black Friday, just like my series from 2018 lol. I'd never been to this station prior, but I saw a picture of it and was curious about the unusual ceiling. This station's ceiling, rather than the standard vaulted type, consists of many smaller arches running along the width of the station. This was done due to the station's shallow depth (and also because it was cheaper).

You'll notice that pretty much all the trains in this video are 2000 or 3000 series with a 6000 series in there. At this time, there were 7000s in service, but far fewer than the total number of them. Thus, all 2000, 3000, and 6000 series trains were running with only 6 cars. They also seemed to have finished 'renovating' all the interiors by replacing all red seats with blue, and sadly ending the practice of having halfcabs at the backs of trains.