Challenges and Considerations
It’s not all perfect yet. AR HUDs face some challenges:
Cost and Complexity: These systems require expensive combiner glass or special windshields, plus projectors with high brightness and resolution. They also need accurate Augmented Reality software to place graphics in the right spot relative to the real world (accounting for car pitch, driver eye position, etc.). This has limited them mostly to high-end cars so far. Over time, costs should drop, but widespread adoption might take a while.
Distraction Potential: While AR HUDs aim to reduce bad distraction, there’s a risk of information overload. Designers have to be careful not to clutter the HUD with too much data. Early user studies suggest keeping the AR content context-specific (e.g., nav when needed, warnings when needed, minimal constant info beyond speed)[101][105]. Also, some drivers might find moving or flashing AR graphics distracting at first. It’s crucial that AR HUD graphics are well-designed, subtle unless important, and don’t obscure real obstacles (they generally avoid drawing opaque images over cars or people, using outlines or arrows instead).
Limited Field of View: Even the best AR HUDs cover maybe 10-15 degrees vertical and 25-30 degrees horizontal of your view. They’re large compared to old HUDs, but still not the entire windshield. If something happens outside that projection area, the HUD can’t point to it. That’s why it’s often focusing on what’s in front of you (most critical). If you’re turning, dynamic HUDs can shift the imagery toward the turn direction, but still, it’s a subset of your full field of vision.
Calibration and Eye Differences: AR HUDs often calibrate to the driver’s eye position (some have cameras to do this). If you sit unusually high or low, or move around, the AR alignment might be off slightly (e.g., the arrow might look a bit to the side of the road). Automakers mitigate this with eye-tracking and by creating a large “eyebox” where the effect works. Still, a very tall or short driver might have a somewhat different AR perspective. These systems usually let you adjust HUD angle and height to suit you. For passengers, the AR might not line up correctly at all, since it’s calibrated for the driver – some images might look weird from the passenger side.
Weather/Display Clarity: Just like regular HUDs, AR HUD projections can be affected by very bright sunlight (washed out graphics) or require the windshield to be clean for best visibility. And if you wear polarized sunglasses, sometimes HUD projections disappear (since they are polarized light)! Automakers address this by adjusting polarization angles, but it can still be an issue.