The ROW once accommodated 4 tracks the entire length (save Pelham Bay Bridge I think), and 6 south of 180th St (the defunct NYW&B). So there’s room for four. But I’d expect them to be to one side or the other to simplify station design, perhaps with Island platforms. I question if the frequencies would require four tracks... a third with occasional passing sidings and meets may be sufficient.
South of Hunts Point, on the Hell Gate Bridge and through Astoria, adding a track may be problematic. The Hell Gate currently only has three tracks, one of which is the Bay Ridge(?) freight track, which runs up to Pelham Bay if IIRC. Jaap do I have that right? So you have to account for CSX and P&W runs along the Branch, too. So you’re only going to get three in most places.
Next stop, Willoughby
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