Since the start of the 2011 season, cars have been allowed to run with an adjustable rear wing, more commonly known as DRS (drag reduction system), a system to combat the problem of turbulent air when overtaking. On the straights of a track, drivers can deploy DRS, which opens the rear wing, reduces the drag of the car, allowing it to move faster. As soon as the driver touches the brake, the rear wing shuts again. In free practice and qualifying, a driver may use it whenever he wishes to, but in the race, it can only be used if the driver is 1 second, or less, behind another driver at the DRS detection zone on the race track, at which point it can be activated in the activation zone until the driver brakes.