Could the Next Generation of Head-Up Displays Be Too Distracting for Drivers?

Transportation experts share their concerns about untested features

21 April 2015

Image: iStockphoto

This article is part of our April 2015 special report on Consumer Electronics, inspired by technologies on display at the 2015 Consumer Electronics Show.

As I reported in “Consumer Electronics May Curb Distracted Driving,” car manufacturers are considering integrating augmented reality and other features into the next generation of head-up displays (HUDs). But they need to proceed with caution, according to Joseph L. Gabbard and Gregory M. Fitch, the researchers interviewed for my article. They work for Virginia Tech’s Transportation Institute, in Blacksburg. Gabbard studies perception, attention, and cognition with respect to new and emerging technologies, and has been working with augmented reality applications for about 15 years. For more than a decade, Fitch has focused on user experience and driver interaction with technology and studies how various applications can help or hinder driver performance.

According to an article published in the Washington Post about the latest HUDs being touted at this year’s Consumer Electronics Show, some carmakers want to add a social media component that would display Facebook and Twitter alerts. Gabbard and Fitch believe this new type of information could lead to distracted driving if the interface is not designed well. These HUDs are promising because they allow drivers to divide their attention between the road and display. However, traditional HUDs, whose images cannot appear past the hood of the car, are limited to displaying a car’s speed, the rpm for manual gear shifting, radio controls, and turn-by-turn directions, have yet to be evaluated in this regard, said Fitch.

“It’s no longer a matter of checking your speed—now there will be these other things being displayed that drivers wouldn’t normally be dealing with,” said Fitch. “There are claims that as long as your eyes are looking forward at a head-up display image, you are safe. That statement needs to be verified because initial research suggests that is not the case.”

Fitch noted research going back to the late 1970s showed that when two HUDs were overlaid on top of each other, people could only focus on one task at a time. “It’s either the front or the back display; pick one,” he said. “We need to ask drivers: ‘How often will you be looking at the head-up display, for how long, and why? Is it driving-related information or is it stuff that doesn’t have anything to do with driving?’ We really need to get an understanding of how people behave with this technology now because we need to inform the manufacturing community about what should be avoided and what rules should be followed from a design standpoint.


In my article I also covered how AR HUDs could display navigation commands, enhanced lane markings, and other graphics as though they are up ahead on the road. An AR HUD could, for example, paint virtual directional arrows that appear to be laid over the road surface, leading the driver to and through a turn.  But, Gabbard made it clear that it’s impossible for the driver to focus on both the AR display and the road at the same time.

“With AR, the driver is physically switching focus,” added Fitch. “You are focusing your lens between the real world and the augmented image.”

Fitch questioned whether manufacturers have thought about how AR displays will control the depth at which the images are presented. He added that no one knows the best depth in terms of comfort, fatigue, safety, or visual attention. “Should speed and time be presented at one depth, Facebook and Twitter updates at another depth, and information such as lane markings at a farther distance?” he asked.

Added Gabbard, “There’s a lot of talk about how AR will make driving safer, but there is still a lot we just don’t know yet. More research is needed on how it affects driving performance, attention, and cognition. Otherwise, car companies could design interfaces that are going to cause problems.”

IEEE membership offers a wide range of benefits and opportunities for those who share a common interest in technology. If you are not already a member, consider joining IEEE and becoming part of a worldwide network of more than 400,000 students and professionals.

Learn More