Go back to the scene and take pictures. You can explain yourself to the court or hire yourself an attorney.
There is no plea bargaining in NYC Traffic Court so you either plead guilty or try the case. If you intend to try the case, I recommend you retain a lawyer familiar with that court.
I am a former federal and State prosecutor and now handle criminal defense and personal injury/civil rights cases. Feel free to check out my web site and contact me at (212) 385-8015 or via email at Eric@RothsteinLawNY.com. The above answer is for informational purposes only and not meant as legal advice.