Examining the Effects of Augmented Reality Traffic Signs on Driver’s Performance and Distraction
MetadataShow full item record
Driving is a complex task that requires full attention and awareness on the road. While traversing roadways, drivers need to be fully attentive by scanning the environment and gathering as many important informational inputs as possible. Driving has three main levels; control, guidance and navigation. Control includes steering and speed control. Guidance can be defined as path following in response to road characteristics and traffic conditions. Whereas navigation comprises trip planning and route adjustments. Those levels differ based on complexity and safety, with navigation being the most complex and least safe . Due to the complexity of navigation, a higher demand on integrating technology in automobile industry arose to simplify this task to the driver as much as possible and increase safety. Thus, in-vehicle navigation systems have emerged and become common vehicle attributes. As driver’s error is identified to be a causal factor in 75 - 95% of the crashes –, the in-vehicle systems can be helpful to the driver by presenting real-time information that is needed at the right place and right time. Avoiding mistakes and violations in driving could help in drastically reducing crash rates. Since Traffic Control Devices (TCDs) are the primary form of communication with drivers, integrating TCDs in the automobile system would be a significant step towards safer and more efficient roadway systems. Taking the in-vehicle systems a step further, Head-up displays (HUD) were introduced to provide drivers with a wider variety of information presented in their line of sight. Those systems comprise a wide range of navigation and warning displays. With the fast pace of automobile technological advancements, augmented reality headup displays (AR-HUD) were introduced and are currently under mass production . It is necessary to test driver performance with any potential system that’s being integrated in automobiles before it gets released. Previous studies have shown that AR-HUD are very effective in communicating real-time necessary information with drivers –. They have improved driver’s performance and compliance with rules and regulations. In addition, ARHUD was proven to be very beneficial in directing driver’s attention and hazard detection. But the question remains: what if the driver receives multiple cues at the same time internally and externally? Would AR-HUD be associated with any sort of distraction? The objective of this research was to examine the effect of AR-HUD traffic signs on driver’s performance and distraction. In addition, the effect of different flashing rates on driver’s reaction is studied. Eighty-eight subjects between 19 and 65 years old participated in this study. Participants were asked to watch 6 different scenarios in a random order, and to respond to a leading braking vehicle by pressing a brake pedal. The leading vehicle would brake unexpectedly at the same time or a little after the AR traffic sign is displayed. A secondary visual detection task was introduced to keep the subjects engaged. All scenarios presented regulatory and warning signs. Scenario A was a traditionally signed segment. Scenario B served as the base case, with a leading vehicle braking without any sign displayed. Scenarios C through F had AR traffic signs displayed at different flashing rates (1Hz, 2Hz and 3Hz) with concurrent or lagged braking of the leading vehicle. Reaction times were compared between Scenario B and C to determine whether the AR signs delay driver’s reaction time to other competing cues. Scenarios D, E and F were compared to determine if reaction times would be equivalent. Lastly, reaction times in scenarios A and C were compared to indicate if there is a significant difference between environment that is traditionally signed and another with AR signs. The results of the three hypotheses tests show that AR signs do not delay driver’s reaction to other external competing cues; rather, they direct their attention to the road. Reaction time is significantly affected by the flashing rate, with the lowest perception/reaction time associated with a sign flash rate of 3 Hz. In addition, driver’s perception-reaction time in a traditionally signed environment is equivalent to that when signs are presented in the AR form.