This study aimed to design visual information for a navigation feature in an Augmented Reality (AR) Head-Up Display (HUD) and integrate the graphics into a Volvo XC60 concept car. The implemented graphics were then tested with users driving the vehicle on public roads. The results were analyzed to determine whether AR-HUD could enhance perception, attention, and safety. User evaluations revealed that AR-HUD helped drivers keep their eyes on the road more frequently when using AR guidance compared to a conventional HUD. Both qualitative and quantitative data indicated that presenting clear and well-timed information for an optimal duration was the key factor in designing human-machine interfaces that support effective user interactions.