Circuit de Monaco downhill again to a double right-hander called "Portier," named after region of Monaco, before heading into the famous tunnel, a unique feature of a Formula One circuit. (Until 2009 only one other circuit, Detroit in 1982–88, featured a tunnel, but the F1 series now includes racing at the Yas Marina Circuit in Abu Dhabi, which presents a shorter tunnel at the exit of the pit lane.) As well as the change of light making visibility poor, a car can lose 20–30% of its downforce due to the unique aerodynamic properties of the tunnel. The tunnel also presents a unique problem
Circuit Paul Ricard circuit in 1983, 1988, 1989 and 1990. The circuit hosted the Formula One French Grand Prix on many occasions, the first of which was the 1971 French Grand Prix. The circuit was also extensively used for testing, especially in Formula One. In 1986, Brabham Formula One driver Elio de Angelis was killed in a testing accident at the fast first turn after the rear wing of his Brabham BT55 had broken off. Although the circuit was not the cause of the crash, it was modified in order to make it safer. The length of the Mistral Straight was reduced from