Something they are trying new this year in NYC was to close off Park Ave from central park to Brooklyn bridge on a few Saturday mornings to allow people walk and ride bikes. Of course I couldn't pass up the opportunity so we got our folding bikes and met up with some friends at the Brooklyn bridge.
Anyone that has not rode a bike on a deserted city street is really missing something. The tall buildings provide shade and it's the perfect speed to enjoy the sights without being so slow as to make it boring. Apparently they were letting people borrow bikes for free but the line was long so I am glad we had our own.
The weather was perfect and the buildings provided shade. We maneuvered around each other as the conversation changed. Since Park Ave. was closed the block of street leading up to it was really unusable too so people were using the side streets for tennis or exercise classes. When we reached Grand Central Station we got to ride on the bridge that goes through the building. (Which is nice since trying to drive and enjoy the sights just is not possible in that area of town.)
When we reached central park we just kept riding and had reached the top and started heading south before I realized how far we had gone. Some of the people were tired so we laid in the grass and talked until some friends we had met earlier caught up. We bought lunch from a local grocery store and enjoyed it in the park. We finished the loop for central park and decided to ride the path next to the Hudson river. (Fairly new path that you don't have to worry about cross traffic.) By the time we reached 14th St. it was 3PM and the other people were tired so we decided to call it a day.
I would have to say, riding through NYC when it is uncrowded is so much more preferable to the subway but for normal days I would take the subway for safety reasons.