What a moving violation citation actually is, the difference between an infraction and a traffic misdemeanour, and the procedures - hearing, written defence, traffic school - for answering one.
A traffic citation is a charge, not a finding. Paying it is a plea of guilty or no contest that goes on the driving record and, in most states, adds points and reaches the driver's insurer. Contesting it means entering a not-guilty plea by the date on the ticket and either appearing for a hearing or, where the state allows it, submitting a written defence. The officer must then establish the violation; if the officer does not appear or the evidence is insufficient, the ticket is dismissed.
Most moving violations are infractions: non-criminal or minor offences carrying a fine, points and sometimes a licence consequence, but no jail. Some driving offences are misdemeanours or worse - reckless driving, driving on a suspended licence, impaired driving, leaving the scene - and those are criminal cases with the rights and consequences that come with them. The distinction decides whether there is a jury, whether counsel will be appointed, and what standard of proof applies; states differ on whether an infraction must be proved beyond a reasonable doubt or by a civil standard, and a few states handle ordinary tickets in an administrative tribunal rather than a court.
Several states let a driver with a clean recent record attend a traffic safety course in exchange for the violation being dismissed or kept off the record, and many courts offer a deferred disposition that dismisses the ticket after a period without further violations. A ticket from another state is not escaped by ignoring it: under interstate compacts most states report convictions to the driver's home state, which treats them as its own, and a failure to appear can produce a suspension at home.
For an ordinary infraction the question is arithmetic the driver can usually do alone: the fine against the insurance and points consequences of a conviction, and whether traffic school or a deferred disposition is available. A lawyer is worth consulting when the ticket is a misdemeanour, when a conviction would push the record to a suspension, when the driver holds a commercial licence, which forecloses most diversion options, or when the citation came out of a crash that may become a civil claim.
Choose your state. Each link opens the directory page for the city in that state with the most currently published law firms in this practice area; a +n beside the city is how many other cities in the state also have one. The list is generated when this page loads, so a state whose listings have lapsed drops out rather than becoming a dead link.