Benefits from Heads-Up Lane Departure Warnings Predicts Safety in the Real-World 2016-01-1443

We examined relative effectiveness of heads-up visual displays for lane departure warning (LDW) 39 younger to middle aged drivers (25-50, mean = 35 years) and 37 older drivers (66-87, mean = 77 years). The LDW included yellow “advisory” visuals in the center screen when the driver started drifting toward the adjacent lane. The visuals turned into red “imminent” when the tires overlapped with the lane markers. The LDW was turned off if the driver activated the turn signal. The visuals could be easily segregated from the background scene, making them salient but not disruptive to the driver’s forward field of view. The visuals were placed adjacent to the left and right lane markers in the lower half of the center screen. Hence, these warnings differed from the industry standard in significant ways, and were implemented in a fixed base, fully immersive, 180 degree forward field of view simulator. 95% confidence intervals for the safety gains from LDW ranged from 1.12 to 1.57 seconds in terms of average correction time across several activations, and 56 to 79 seconds in terms of total exposure time to the warnings across the whole drive. Older adults were generally slower to correct lane departures (by .47 seconds on average, p < .05) and were exposed to LDW for longer total durations than younger adults. However, magnitude of safety gains from LDW was similar for older and younger drivers. Although there was no differential improvement from LDW given participant age, LDW improved older driver’s performance to levels comparable with younger drivers without LDW. Total exposure time to LDW (pearson-r >=.45, p <.001) but not average correction time (pearson-r < .17, p=.185) predicted total number of safety errors committed in a standard on-road drive in the real-world.