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In motorsports, a pit stop is where a racing vehicle stops in the pits during a race for refuelling, new tyres, repairs, mechanical adjustments, a driver change, as a penalty, or any combination of the above. Not all of these are allowed in all forms of racing. The pits usually comprise a pit lane which runs parallel to the start/finish straight and is connected at each end to the main track, and a row of garages (usually one per team) outside which the work is done. Pit stop work is carried out by anywhere from five to twenty mechanics (also called a "pit crew"), depending on the series regulations, while the driver often waits in the vehicle (except where a driver change is involved or in Motorbike racing). Depending on the circuit, the garage may be located on pit lane or in a separate area. Most North American circuits feature a pit lane with a number of pit stalls (typically 30-50) and a pit wall that separates the pit lane from the infield, with the garages (if used) on a separate road in the infield. In races where there are different series racing together, each series has its own separate garage or are parked in their own area. Circuits in other parts of the World (used in Formula One) typically have the individual garages open directly onto the pit lane through the team's assigned pit box. In American English, it is common to drop the definite article and just refer to "pit road", whereas in British English one would always refer to "the pit lane". A further difference is that in British English, the term "pit box" is universally used, whereas in American English, one would say "pit stall". It is important to note that in NASCAR, a pit box is a tool (see below), though there is a definitive term used for them. Where it is permitted, refuelling is often an important purpose of a pit stop. Carrying fuel slows down a vehicle and there is often a limit on the size of the fuel tank, so many races require multiple stops for fuel to complete the race distance in the minimum time. Changing tyres is also common to permit the use of softer tyres that wear faster but provide more grip, to use tyres suitable for wet conditions, or to use a range of tyres designated by the rules. Teams will aim for each of their vehicles to pit following a planned schedule, with the number of stops determined by many factors such as fuel capacity, tyre lifespan, and the trade-off between time lost in the pits versus time gained on the track due to the benefits of pit stops. Choosing the optimum pit strategy of how many stops to make and when to make them is crucial in having a successful race. It is also important for teams to take competitors' strategies into account when planning pit stops, to avoid being held up behind a competitor where overtaking is difficult or risky. An unscheduled or extended stop, such as for a repair, can be very costly for a driver's chance of success, because while they are stopped for service, competitors remaining on the track are gaining time on them. For this reason, the pit crew often undergo intensive training to perform operations such as tyre changes as quickly as possible leading to pit stops, for example in Formula 1, where the car is only stationary for a few seconds for a regular pit stop. In most series the order of the order of the teams' pit boxes is assigned by points standings, race results, or previous qualifying results before the start of the race. In NASCAR and in INDYCAR's Indianapolis 500, typically pit assignments are made after qualifying, with the fastest qualifiers choosing their pit stall first. == General strategy == In any racing series that permits scheduled pit stops, pit strategy becomes one of the most important features of the race; this is because a race car travelling at 100 miles per hour (160 kilometres per hour) will travel approximately 150 feet (45 metres) per second. During a ten-second pit stop, a car's competitors will gain approximately one-quarter mile (400 metres) over the stopped car. However, the car that made the additional pit stop will run faster on the race track than cars that did not make the stop, both because it can carry a smaller amount (and thus lower weight) of fuel, and will also have less wear on its tyres, providing more traction and allowing higher speeds in the corners. In racing series where teams have their choice of different compound tyres, the lower tyre wear may be enough to allow the team to choose to use a tyre with a softer rubber compound that provides increased grip at the expense of faster wear; going longer between stops may even cause enough wear on the softer tyre to cause the tyres to fail. Because of this, race teams plan a pit strategy prior to the start of every race. This is a schedule for each car's planned pit stops during the race, and takes into account factors such as rate of fuel consumption, weight of fuel, cornering speed with each available tyre compound, rate of tyre wear, the effect of tyre wear on cornering speed, the length of pit road and the track's pit road speed limit, and even expected changes in weather and lighting conditions. The pit strategy does not just include a schedule of ''when'' pit stops will happen; it also includes what service and adjustments are scheduled for each pit stop, particularly in endurance racing, where scheduled changes of wear-limited parts such as brake pads may be planned for specific points during the race. The pit strategy is calculated carefully so that the amount of time to be "given away" to other competitors in pit stops is balanced out by the time gained while on the track, resulting, theoretically, in the shortest possible time to cover the scheduled distance. However, a team's pit strategy is not a fixed, immutable thing; it is subject to change during the race to take into account the unpredictable events that happen in every race. In road racing, for example, if the weather changes from dry to rain, teams will be forced to recalculate their pit strategy based on the unscheduled stop to change from dry-weather "slick" tyres to treaded wet-weather tyres. Safety car periods often see mass pit stops by many teams, hoping to take advantage of the slowed pace to reduce the ground lost to other teams while making pit stops; this forces teams that do so to immediately recalculate their pit strategy to optimise it for the remaining race distance after the stop. Even when a team chooses not to take advantage of the opportunity to stop during a full-course caution, it can still result in significant changes to pit strategy; under caution, the cars run at a reduced speed that results in greatly reduced tyre wear and fuel burn for a distance travelled. Depending on the circumstances, this may be enough for a team to gain more by choosing not to pit, hoping that the reduced fuel burn and tyre wear will allow them to make one pit stop fewer than the other teams, allowing them to gain distance and time on their opponents. At tracks noted for frequent full-course cautions, teams may even plan their entire race strategy around this, using a suspension and aerodynamic setup suited to short sprints instead of extended runs to gain positions in the short bursts of green-flag racing, and planning their pit strategy on the assumption that cautions will extend their fuel mileage and tyre wear enough to make fewer stops than would otherwise be needed to complete the race distance. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「pit stop」の詳細全文を読む スポンサード リンク
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