According to traffic accident data, the majority of severe road accidents occur at night. It is, therefore, of great importance to use available technology to contribute to road safety by improving the visual conditions provided by vehicle headlights. This paper presents the hardware in the loop simulation of an Adaptive Headlight System for motor vehicles. The Adaptive Headlight System is an active safety system, where the headlamp orientation control system rotates the right and left low beam headlights independently and keeps the beam as parallel to the curved road as possible to provide better night time visibility. In the paper, the real time vehicle and road models used are presented first. The hardware-in-the-loop simulation setup proposed for testing the adaptive headlight concept is then given. Real time simulations using this simulator are used to illustrate the approach.