I'm guessing that it had to do with the neighborhood that it found itself in. The next stop outbound (Northampton) retained it's center island construction, but Wash at this point is considerably wider, giving more of a distance from multi-storied buildings. At Dover/Wash, there existed the Roosevelt Hotel, at the time an upscale quality place with multiple floors. Trying to read between the lines, the hotel may have complained that rapid transit cars rattling by mere inches from the hotels third floor windows was detrimental to business, already established prior to the El's construction I believe, and a way of pushing the cars away somewhat and insulating them was to put them in the middle as opposed to the edges. Admittedly, the El did bring on a certain seediness into what was a thriving industrial and commercial area anyway, with frequent drunken habitués wandering about. The hotel suffered a major fire in the '70's with loss of life and had to be razed.
~Paul Joyce~
Moderator: Toy Trains, Model Railroading, Outdoor and Live Steam
Paul Joyce passed away in August, 2013. We honor his memory and his devotion at railroad.net.