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 in length to just over , and the fast sweeping Verierre curves where de Angelis had crashed were bypassed. Effectively, after the start, instead of heading into the left hand Verierre sweeper, cars now braked hard and turned sharp right into a short run that connected the pit straight to the Mistral. This changed the circuit length for a Grand Prix from to just . This also had the effect of cutting lap times from Keke Rosberg's 1985 pole time of 1:32.462 in his Williams-Honda turbo, to Nigel Mansell's 1990 pole time of 1:04.402 in his V12 Ferrari.