The Land Speed Record (or absolute land speed record) is the highest speed achieved by a wheeled vehicle on land. There is no single body for validation and regulation; in practice, the Category C ("Special Vehicles") flying start regulations are used, officiated by regional or national organisations under the auspices of the Fédération Internationale de l'Automobile. The record is standardised as the speed over a course of fixed length, averaged over two runs (commonly called "passes"). Two runs are required in opposite directions within one hour, and a new record mark must exceed the previous one by at least one percent to be validated. There are numerous other class records for cars; motorcycles fall into a separate class.
The first regulators were the Automobile Club de France, who proclaimed themselves arbiters of the record in about 1902.
Different clubs had different standards and did not always recognise the same world records until 1924, when the Association Internationale des Automobile Clubs Reconnus (AIACR) introduced new regulations: two passes in opposite directions (to negate the effects of wind) averaged with a maximum of 30 minutes (later more) between runs, average gradient of the racing surface not more than 1 per cent, timing gear accurate within 0.01sec, and cars must be wheel-driven. National or regional auto clubs (such as AAA and SCTA) had to be AIACR members to ensure records would be recognised. The AIACR became the FIA in 1947. Controversy arose in 1963: Spirit of America failed on being a three-wheeler (leading the Fédération Internationale de Motocyclisme to certify the record when the FIA refused) and not wheel-driven so the FIA introduced a special wheel-driven class. No holder of the absolute record since has been wheel-driven.
Craig Breedlove's mark of 407.447 miles per hour (655.722 km/h), set in Spirit of America in September 1963, was initially considered unofficial. The vehicle breached the FIA regulations on two grounds: it had only three wheels, and it was not wheel-driven, since its jet engine did not supply power to its axles. Sometime later, the Fédération Internationale de Motocyclisme created a non-wheel-driven category, and ratified Spirit of America's time for this mark. On 27 July 1964, Donald Campbell's Bluebird CN7 posted a speed of 403.10 miles per hour (648.73 km/h) on Lake Eyre, Australia. This became the official FIA LSR, although Campbell was disappointed not to have beaten Breedlove's time. In October, several four-wheel jet-cars surpassed the 1963 mark, but were eligible for neither FIA nor FIM ratification. The confusion of having three different LSRs lasted until 11 December 1964, when the FIA and FIM met in Paris and agreed to recognise as an absolute LSR the higher speed recorded by either body, by any vehicles running on wheels, whether wheel-driven or not. Thus, Art Arfons' Green Monster was belatedly recognised as the absolute LSR holder, Bluebird the holder of the wheel-driven land speed record, and Spirit of America the tricycle record holder. No wheel-driven car has since held the absolute record