Some bike lanes in NYC have two lanes as well. I don't believe 1st Ave does though.
edit: I misunderstood. Yes, if the bike lane is contraflow of course use it that way. Everyone expects bikes from the "wrong way" in that situation. It's all about minimizing surprises to anyone in or near the street.
edit: I misunderstood. Yes, if the bike lane is contraflow of course use it that way. Everyone expects bikes from the "wrong way" in that situation. It's all about minimizing surprises to anyone in or near the street.