A method of operating a head-up display system, head-up display system

The invention relates to a method of operating a head-up display system (1) of a vehicle, in particular motor vehicle (2), wherein the vehicle outside of the vehicle monitored and upon detection of a danger zone (15) a warning stationary correctly displayed on a windshield of the vehicle becomes. It is provided that by means of at least one suitable sensor (4) examined the road condition to be traveled by the vehicle roadway (5) and upon detection of a critical road condition by site correct Expanded the roadway (5) at least partially according to its state is marked. The invention further relates to a head-up display system.