It is a criminal offense to use or operate a motor vehicle, boat, airplane, motorcycle, or other motor-propelled vehicle without the consent of the owner or other person authorized to give consent. This crime is generally known as (1) unauthorized use of a motor vehicle, (2) unauthorized use of a vehicle, or (3) joyriding.

The difference between this crime and the crime of theft is that the state does not have to prove a person charged with unauthorized use of a motor vehicle intended to keep the vehicle or permanently deprive the owner of the vehicle.

Laws regarding the unauthorized use of a motor vehicle vary from state to state and are generally found in a state’s statutes—often in the penal or criminal code or the vehicle code.

In New Jersey, the unauthorized use of a motor vehicle, often referred to as 'joyriding,' is a distinct criminal offense from theft or grand theft auto. Under New Jersey law, specifically N.J.S.A. 2C:20-10, it is illegal to take or operate a vehicle without the owner's consent. This statute makes it clear that the crime of unauthorized use does not require the intent to permanently deprive the owner of the vehicle, which is a key element in vehicle theft charges. The offense can apply to various motor-propelled vehicles, including cars, boats, and motorcycles. Penalties for unauthorized use of a vehicle in New Jersey can range from a disorderly persons offense to a fourth-degree crime, depending on factors such as prior offenses and the value of the vehicle used without authorization. The severity of the punishment reflects the state's interest in protecting property rights and ensuring the lawful use of vehicles.