I usually see the term "bench seating" to describe those seats in which passengers sit sideways to the direction of travel and are affixed to the wall like, y'know, benches. Though I don't know the corresponding term for the dominant (on Metro anyway), window-and-aisle, inner-and-outer, seat pairs. They are supposedly a legacy of Metro's early years when planners envisioned GS-13s taking long rides from their bucolic 'burbs to the downtown DC office and back. They're woefully ill-suited to the large number of shorter trips to diverse destinations. Compared with many other busy systems, Metro has a lot of padded seats that require one person to move to accommodate the other, and few doorways. They become a pinch point and increase station "dwell time" significantly. I've also, ahem, noticed that doorways designed in the slimmer 1970s need to be wider today.