You can get to most of Manhattan under 125th st and almost all of northwest Brooklyn without leaving a bike lane: http://www.nyc.gov/html/dot/html/bicyclists/bikemaps.shtml

Even in my neighborhood in Queens I can get into Manhattan with only a 3 block stretch outside of a bike lane.

Obviously there is going to be more traffic than Stockholm, we have almost 8 million more residents.

There is a already a large effort to create bike lanes in the city. The city website lists current bike lane projects: http://www.nyc.gov/html/dot/html/bicyclists/bike-projects.sh...