On another thread, there was a discussion the number of bathrooms in Broadway theatres. Too few. That discussion went in another direction. I want to give a reason why there are fewer than required. Plays and musicals used to have more intermissions. Often two and not unusually more. The three act play was standard. Effectively now, the three act play is in two acts with I and Ii before the intermission. Revivals now follow this. Musicals are usually in two acts and frequently without intermissions at all; the same goes for some plays. Why the change? Part of it is the cost of going overtime; part of it is how works are now conceived. The last 3 act musical on Broadway was the 1971 revival of No, No, Nanette. The last new Broadway musical in three acts was The Most Happy Fella (now performed in 2). Cabaret was in three acts out of town, but opened on Broadway in 1966 in two. Structurally speaking, a three act structure is still common but not in presentation. Another reason for the change is the way scenery was changed. Intermissions provided the time needed. Automation renders it unnecessary. As well, the older post WW iI musicals often followed a pattern with every other scene in front of a drop or a traveler.