Why Greenways?
A greenway is a linear open space, such as a path or trail, which links parks and communities around the City, providing public access to green spaces and the waterfront. Greenways expand recreational opportunities for walking, jogging, biking, and in-line skating.

In 1993, the City of New York had a vision to create 350 miles of landscaped bicycle and pedestrian paths that would crisscross the City's five boroughs and enrich the lives of all New Yorkers. Currently Parks has built over 100 miles of the proposed greenway system. Greenways answer the growing public demand for safe and pleasant ways to travel about the City. These trails allow one to get to work or school, shop or do errands, or to reach the waterfront, parks, beaches, and museums.

http://www.nycgovparks.org