The Impact of Distraction on an Intersection Crossing Assist System

The current study examines the impact of drivers’ use of an in-vehicle intersection crossing assist system under demanding cognitive load conditions. The use and adherence to the assist system is examined through intersection crossing driving performance measures. Furthermore, the impact of distraction is examined for younger and older drivers. The results suggest a more conservative approach to the crossing of rural intersections when using the assist system, a finding which was not altered by cognitive load

Examination of the Efficacy of Proximity Warning Devices for Young and Older Drivers

OBJECTIVESThe study was conducted to examine the efficacy of uni- and multi-modal proximity warningdevices for forward object collision and side-object detection for young and older adult drivers.METHODSTwo experiments were conducted, each with 20 young (18 to 30 years of age) and 20 older (61to 80 years of age) healthy and high functioning drivers. In each, participants drove a series ofbrief (~ 4 minute) highway scenarios with temporally unpredictable forward and side collisionevents (i.e., other vehicles). The experiments were conducted in a fixed-base Drive Safetysimulator with a 135-degree wrap-around forward field and a 135-degree rear field. Light crosswindswere included in Experiment 1, while heavier crosswinds were introduced in the secondexperiment. A secondary visual read-out task from an in-vehicle LCD display was also includedin the second experiment.In Experiment 1, potential collision events were signaled 2.2 seconds before impact by visual,auditory, auditory+visual or tactile+visual warnings that were spatially mapped to the location ofthe obstacle (left, right or center). A control condition in which subjects drove without anyproximity warning device was also included in the experiment. Experiment 2 included thecontrol, auditory+visual and visual warnings from Experiment 1.A number of dependent measures were collected, including velocity, lane position, steeringwheel movement, brake and accelerator position. However, we will focus on the response time(as measured by steering wheel deflections or removal of the foot from the accelerator) topotential collision events as well as the number of collisions in different experimental conditions.RESULTSIn both Experiments 1 and 2, the auditory+visual warning device produced the most rapidresponse and also resulted in the fewest collisions. The reduction in response time and collisions,relative to the no-warning control condition was larger in Experiment 2 than in Experiment 1, likely as a result to the more challenging driving scenarios (with the higher and unpredictablewinds and introduction of the secondary task) in this experiment.Older adults responded just as quickly as younger adults to the potential collision events in bothof the experiments. This is a very surprising finding given a voluminous laboratory literature,which suggests that older adults display slower responses than younger adults on almost any taskthat has been examined in the laboratory.In an effort to understand the age-equivalent response times to collision events, we asked youngand older participants from the first experiment to take part in an additional experimental sessionin which they made simple and choice responses to visual and auditory events in a soundattenuated subject booth. Older adults were substantially (~ 35%) slower in each of these simpleand choice tasks performed in the laboratory.Older adults displayed the same performance benefits (in terms of speeded response time andreductions in collisions) from the proximity warning devices, and particularly theauditory+visual device, in both of the experiments as younger adults. However, in Experiment 2,older adults displayed these benefits by neglecting the number read-out secondary task.CONCLUSIONSThere are several important conclusions from the present study. First, proximity warningdevices, and particularly auditory+visual devices, can substantially speed response time andreduce potential collisions in simulated driving. This is an important observation that has thepotential to reduce automobile accidents. Second, both younger and older adults benefit from theproximity warning devices. Such a finding suggests, that at least for individuals with normalvision and hearing, these devices might have substantial utility across a wide variety of drivers.Third, quite to our surprise, older adult drivers responded just as quickly, with and without theproximity warning devices, to potential collision events as younger drivers. Interestingly, ageequivalencein response time to potential collisions was not observed in simple and choiceauditory and visual laboratory response time tasks. Such data tentatively suggests that experienceand expertise in driving may act as a moderator of age-related decline in general slowing.Given the unpredictable nature of the potential collision events in our study, older drivers may becapitalizing on high levels of vigilance and attentional focus on driving relevant tasks to maintaintheir ability to rapidly respond to collision events. This hypothesis is supported, in part, by thedecrements in secondary task performed observed for the older but not for the younger adults inExperiment 2.The results from the present study are encouraging both with respect to the utility of proximitywarning devices as a means to enhance driver safety as well as for their potential application todrivers of different ages and experience levels. However, clearly additional research will beneeded to verify these results in more challenging simulator and on the road driving situations

Aging and the Effects of Conversation with a Passenger or a Caller on Simulated Driving Performance

A total of 96 pairs of older and younger drivers participated in a study assessing the effects of conversation on the driving performance of older and younger drivers in a simulated city environment. These effects were investigated while drivers conversed with an in-vehicle passenger or an outside-vehicle caller. All of the passengers completed three separate, counterbalanced blocks of tasks that consisted of two single-task blocks (driving only and conversing only) and one dual-task block (driving and conversing). The results showed greater variability in velocity, lane keeping and steering control under single-task than under dual-task conditions. Drivers also showed greater average velocity and greater deviation from the center of the lane under single-task than under dualtask conditions. However, when crossing an intersection, a task requiring greater attentional resources, drivers exhibited a cost due to the dual task. Our data are consistent with the literature, which suggests that a secondary task may aid in the performance of a routinized task but may also impose costs if the primary task requires significant attentional resources. Older drivers exhibited greater variability in velocity, stayed closer to the center of the lane, and waited longer to cross intersections than their younger counterparts, suggesting that they compensate for their declining perceptual and cognitive abilities through changes in driving behavior. Drivers exhibited greater variability in steering under singletask conditions when talking to an outside-vehicle caller, and older drivers showed greater variability in velocity when conversing with an outside-vehicle caller

Aging and the Effects of Conversation With a Passenger of a Caller on Simulated Driving Performance

126 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009.The current study investigates the effects that conversation has on driving performance of older and younger drivers. In addition, the effects that the location of the conversation partner has on driving performance are also being explored. Furthermore, the quality and accuracy of the speech task were investigated as well as the extent of participant's involvement in the speech task in the form of memory recall. 96 pairs (driver and their conversation partner) of older and younger participants engaged in a story retelling task in a driving simulator. The results showed better lane keeping and more stable velocity control when drivers conversed with their partner compared to driving only. Drivers also showed faster average velocity under single-task than under dual-task conditions. Older drivers showed evidence of modulation in difficult driving conditions suggesting that they compensate for their declining perceptual and cognitive abilities through changes in driving behavior. Drivers exhibited a cost in accuracy of speech task performance when driving, providing evidence of prioritization. The results showed a decline in the accuracy of story telling by drivers and in the drivers' memory for stories told to them by their non-driving partners. Also, speech production suffered an additional cost when the difficulty of driving increased. Drivers produce more fluent speech when conversing with cell-phone caller than with passenger, although the location of conversation partner did not impact driving performance.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD