Yes, well, you have a point; shoulders are, on a normal person, wider than the hips. So we would have to add an inch or two each side, the exact amount depending on the exact width of the seat at that point, plus 50% of the gap between it and the next seat, on each side. Dimensions for the middle seat in a row of three would apply to the two other seats in the row.
The underlying principle is that no passenger should encroach on another passenger's space on each side, or stick out to be clobbered (unintentionally, ho, ho, ho) by the trolley.
Last edited by Capot; 24th Nov 2012 at 23:10.