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 Massachusetts, the unauthorized use of a motor vehicle, often referred to as 'joyriding,' is a criminal offense under Massachusetts General Laws Chapter 90, Section 24(2)(a). This law makes it illegal for a person to use, take, or operate a motor vehicle without the authority of the owner. Unlike theft or grand larceny of a motor vehicle, the crime of unauthorized use does not require the prosecution to prove that the individual intended to permanently deprive the owner of the vehicle. The focus is on the lack of consent from the owner for the use of the vehicle. Penalties for unauthorized use of a motor vehicle in Massachusetts can include fines, imprisonment, or both, and the severity of the punishment can vary based on the circumstances of the offense and the individual's criminal history.