To the best of my knowledge, and just speaking from New York law, unless you're going to and from the pistol range, you should not be carrying the pistol. And that is further limited to the county. Of course, in NY it's virtually impossible to obtain a CCW unless you transport large amounts of cash as part of your business.
In any event, the others have all made good suggestions. As retemple and Immortal indicate, keep the weapon in its closed case in the trunk of your car or the back of your SUV. Although I would disagree about advising a police officer about such if you're stopped for merely a traffic violation. In my opinion, present your license, registration and proof of insurance and no more. Remain calm, be reasonable, don't say anything incriminating (But sir, I was only five MPH over the speed limit... DOH!), plead your case, ask for only a warning this time and you may just go on your way with one.
Regards,
RW