It depends. Can a police officer, who trains extensively to so, with many different types of knives, open your knife one handed?
If so, you would be guilty of illegally possessing a “gravity knife” according to the NYC DA. He has extorted hundreds of thousands of dollars for his personal office “knife safety” slush fund doing this for the past several years.
People with knives of blade length as small as 1 inch have been arrested and prosecuted. Even the Village Voice came out for a reform of this law.
http://gunwatch.blogspot.com/2015/02/ny-reform-of-gravity-knife-law.html
Is that the main criteria? The knife I have can be opened one-handed, but you have to flick it pretty hard with your wrist.
It's a Spyderco knife with the large opening on the blade to push it open with.
I have no plans (EVER) to go to NYC, so this is mainly an academic discussion.