9W might be OK for people living in Manhattan, but for me its around 24 miles and 2+ hours away on a bike. Doing any kind of hard training and then facing 2 hours of riding back is not something I would consider realistic. Even by car, it's over an hour with all of the traffic in the city. This might be OK for once in a while excursion, but definitely not everyday/weekend.

Jamaica Bay - are we talking about the bikeway along Belt Pkwy? As noted above, sand by Plum beach and some of the bridges are really hair raising. I do have to say, there might be stretches long enough for some quick intervals now that they redone some of the areas, but unfortunately for me, I first have to get through Plum beach sand.