Well, first off, definitely make sure that you do include your violation in the appropriate section. To leave it off would not only bring your conduct, but also your honor, into question when it does show up on your background check.
If your offense is a misdemeanor, I believe your application will have to go before the Character Review Committee. If this happens, you will be asked to write up a summary of the violation and what you learned from it. Outcomes from the CRC can range from the violation having absolutely no effect on your application to a recommendation that you not be considered for admission (depending on the severity of the violation).
If your offense is a minor traffic violation (with fine under $200), I think it would be safe to say that it won't have much of an effect on your application at all.
You can't control the past but you can control the future, so don't do anything that would cause you to receive another citation (this includes speeding).
The best sources of information, of course, are your Blue and Gold Officer (BGO) and your Regional Director (contact info for both can be found in the Candidate Information System).
Best of luck!