Governments and private organizations have developed car classification schemes that are used for innumerable purposes including regulation, description and categorization, among others. This article details commonly used classification schemes in use worldwide.
Vehicles can be categorized in numerous ways. For example, by means of the body style and the "level of commonality in vehicle construction as defined by number of doors and roof treatment (e.g., sedan, convertible, fastback, hatchback) and number of seats" that require seat belts to meet safety regulations.
Regulatory agencies may also establish a vehicle classification system for determining a tax amount. In the United Kingdom, a vehicle is taxed according to the vehicle's construction, engine, weight, type of fuel and emissions, as well as the purpose for which it is used. Other jurisdictions may determine vehicle tax based upon environmental principles, such as the user pays principle. In another example, certain cities in the United States in the 1920s chose to exempt electric-powered vehicles because officials believed those vehicles did not cause "substantial wear upon the pavements."
Another standard for road vehicles of all types that is used internationally (except for Australia, India, and the U.S.), is ISO 3833-1977.
In an example from private enterprise, many car rental companies use the ACRISS Car Classification Code to describe the size, type and equipment of vehicles to ensure that rental agents can match customer needs to available vehicles, regardless of distance between the agent and the rental company or the languages spoken by either party. In the United States, since 2010 the Insurance Institute for Highway Safety uses a scheme it has developed that takes into account a combination of both vehicle shadow (length times width) and weight.
The United States National Highway Traffic Safety Administration (NHTSA) separates vehicles into classes by the curb weight of the vehicle with standard equipment including the maximum capacity of fuel, oil, coolant, and air conditioning, if so equipped.
The United States Federal Highway Administration has developed a classification scheme used for automatically calculating road use tolls. There are two broad categories depending on whether the vehicle carries passengers or commodities. Vehicles that carry commodities are further subdivided by number of axles and number of units, including both power and trailer units.