(To a much lesser degree, more people on the bikes may also mean less people driving for short trips, though I assume in Manhattan most riding the Citi bikes would have taken public transportation if there were no Citi bikes.)
Raises hand. I would be on the subway if it weren't for citibike. It's done wonders in terms of being able to relax - both heading to work and heading home. Something piling on an already crowded train doesn't allow for. Last year I managed to ride into the first week of January. After a hard fall on the Brooklyn Bridge 2 years ago I no longer venture out when there's snow on the ground. Last year the combination of snow and unrelenting cold kept me from the citibike until sometime in March. I hope we have a mild winter this year.