A traffic ticket or citation is a document written by a police officer that alleges the driver (operator) of a motor vehicle committed a violation of state or local traffic laws while the motor vehicle was moving (also known as a moving violation).

A ticket or citation issued to the owner of a motor vehicle for violation of a state or local law that is alleged to have occurred while the vehicle was not moving (such as a parking violation)—and tickets or citations issued to pedestrians or operators of bikes, skateboards, or other non-motor vehicles for illegal use of streets, sidewalks, and other driveways—are known as nonmoving violations. A ticket or citation for illegal parking or another nonmoving violation usually requires the person to pay a fine by a certain date or appear in court to contest the charge.

A traffic ticket or citation usually requires the driver to pay a fine by a certain date or appear in court to contest the charge. In some states traffic violations are low-level misdemeanor criminal offenses—but in other states traffic tickets are classified as infractions or civil offenses. If a ticket or citation is classified as a criminal offense the driver's guilt or innocence will be determined by a jury or judge. But if a ticket or citation is classified as a civil infraction, violation, or offense the driver will be determined (adjudged) to be responsible or not responsible.

In Massachusetts, traffic tickets or citations for moving violations are issued by police officers when a driver is suspected of violating state or local traffic laws while the vehicle is in motion. These violations can range from speeding to running a red light. Nonmoving violations, on the other hand, pertain to infractions that occur when the vehicle is stationary, such as parking violations, or to offenses committed by pedestrians or operators of non-motor vehicles. For both moving and nonmoving violations, the recipient of the ticket is typically required to either pay a fine by a specified date or appear in court to dispute the charge. In Massachusetts, most traffic violations are considered civil infractions rather than criminal offenses. This means that the determination of responsibility is made by a judge or a hearing officer, rather than by a jury. However, some serious traffic offenses, such as operating under the influence (OUI), can be classified as criminal and may require a court trial to establish guilt or innocence.