Hitchhiking in New York state is illegal. Or de facto illegal. If you can, avoid hitchhing in the South of this state. Around Albany you probably only get rides from cops.
People in the North, especially in the Adirondacks, are very friendly though. You can also do some great wild camping. (If you hear bells, don't worry, just start counting.)
When coming down from Quebec, going to New York City it's probably better to stick on the I-9, on which you can easily walk (and legally, if you weren't hitchhiking), instead of the I-87.
It is illegalEdit
We do not drive and were stuck out somewhere there are no taxis or public transportation. So instead of walking with a 2 year old and a 6-month pregnant wife, we decided to hitch-hike. Cops detained us, took our IDs, ran background checks, and almost arrested us. He was VERY angry. Said hitch-hiking has ALWAYS been a crime in New York.
Legal, but be CarefulEdit
Laws relating to hitchhiking or pedestrian travel on highways in New York are similar to the Uniform Vehicle Code (UVC), except where it comes to the New York State Thruway.
What this means is: It is technically legal to hitchhike from the shoulder of a road or an on-ramp if no sign is posted prohibiting pedestrians. When it comes to the Thruway- which includes the major highways of I-87, I-90 and I-95- it is not only illegal to hitchhike the shoulder, but also near the entrance to these highways. A hitchhiker must stand outside of the Thruway property.
Border on the I-87Edit
Try to get a ride on the Canadian side. Forget about hitching on the other side of the border, like you would do in civilized countries. Once you're taken by American customs personnel you can't walk back. They will be very confused and your best bet is that someone tells you to walk to the truck stop at exit 43. There are also gas stations at exit 42, which is not far.