Because the race was rescheduled and the longer period of darkness, the Automobile Club de l'Ouest (ACO) permitted one battery change. With high speed being such a talking point, Ford volunteered to sponsor a major road realignment on the main straight, installing a chicane just before the pitlane. The changes added at least 10 seconds to a lap, as well as causing greater wear on tyres and brakes. Although the track had been widened and safety features of the track improved in the aftermath of the 1955 disaster, this was the first significant layout-change to the circuit since 1932. Diverting the racing away from the pits also significantly increased the safety of the pit-crews. Finally, in line with the global racing trend, commercial advertising was now allowed on cars.