All this month, the Getting Around series will look at the unwritten rules for traveling in and around New York City, whether it's underground, on the ground, or in the air. Billie Cohen, deputy editor of Time Out New York, is the unwritten rules guru for the series. This Week: Biking, driving and walking. What are your rules for behaving on the road and, more importantly, how can bikers/drivers/walkers best get along? Comment below!