Help: got ticket for obstruction intersection NY

When I arrived the intersection,the light is green and there is no traffic at all,then when I drived at the middle of the intersection, a policeman stop a car that is two car in front of my car, and I could not change the line, because there are some cars passed by,so I could not go forward nor change the line, then the policeman gave me the ticket.

I chose not guilty then go to the Judge point that is because the policeman stop car make the traffic but the Judge would not listen to my explaination, insist the same fine. I asked him if I am not agree what his decision, what shall I do. He said I can appeal. My question is that useful? Thanks!