Does Exposure to Distraction in an Experimental Setting Impact Driver Perception of Cell Phone Ease of Use and Safety?

We examined drivers’ perception of the ease and safety of cell phone use while driving before and after exposure to distraction in an experimental setting. During the study, each driver reflected on driving and task performance while engaged in conversation-like and arithmetic distraction tasks on a handsfree and hand-held cell phone. Hands-free phones were consistently rated easier to use and safer than hand-held cell phones by both age groups, despite equivalent decrements in driving performance. Younger drivers consistently rated cell phones to be easier to use and safer than did older drivers. After exposure to distraction, younger drivers’ perception of the ease of use declined relative to their initial ratings; however, there was no corresponding change in the ratings of safety. In contrast, older drivers’ perception of ease or safety did not change significantly post-exposure. A priori subjective ratings on various dimensions of driver skill and distraction were also examined with respect to age-related differences

Multiple Resource Modeling of Task Interference in Vehicle Control, Hazard Awareness and In-vehicle Task Performance

We describe a computational model of multiple task performance used to predict task interference and subsequent decrements in performance, based on the resource demands of a particular task (i.e., the difficulty) as well as the competition between tasks over limited and overlapping resources. We describe the model components, the computational aspects, and further validate it with data from a simulated driving study

Awareness of Performance Decrements Due to Distraction in Younger and Older Drivers

Although many studies have documented the performance decrements associated with driver distractions, few have examined drivers’ awareness of these distraction effects. The current study purports to measure how wellcalibrated drivers are with respect to their own performance when distracted. Forty drivers completed a series of tasks on a hand-held or hands-free cell phone while driving an instrumented vehicle around a closed test track. Subjective estimates of performance decrements were recorded and compared to actual decrements observed on multiple measures of driving performance. Although their driving performance suffered in dual-task conditions, drivers were generally not well-calibrated to the magnitude of the distraction effects (r = -.38 to .16). In some cases, estimates of distraction were opposite of the observed effects (i.e., smaller estimates of distraction corresponded to larger performance deficits). There were some age and gender differences. We discuss the implications of these findings for potential mitigation strategies for distracted driving

Age-Related Differences in Vehicle Control and Eye Movement Patterns at Intersections: Older and Middle-Aged Drivers

Older drivers are at increased risk of intersection crashes. Previous work found that older drivers execute less frequent glances for detecting potential threats at intersections than middle-aged drivers. Yet, earlier work has also shown that an active training program doubled the frequency of these glances among older drivers, suggesting that these effects are not necessarily due to age-related functional declines. In light of findings, the current study sought to explore the ability of older drivers to coordinate their head and eye movements while simultaneously steering the vehicle as well as their glance behavior at intersections. In a driving simulator, older (M = 76 yrs) and middle-aged (M = 58 yrs) drivers completed different driving tasks: (1) travelling straight on a highway while scanning for peripheral information (a visual search task) and (2) navigating intersections with areas potential hazard. The results replicate that the older drivers did not execute glances for potential threats to the sides when turning at intersections as frequently as the middle-aged drivers. Furthermore, the results demonstrate costs of performing two concurrent tasks, highway driving and visual search task on the side displays: the older drivers performed more poorly on the visual search task and needed to correct their steering positions more compared to the middle-aged counterparts. The findings are consistent with the predictions and discussed in terms of a decoupling hypothesis, providing an account for the effects of the active training program

A Preliminary Examination of Age-Related Differences in Perceived Complexity at Fatal-Crash Intersections

Younger and older drivers are both overrepresented in fatal crashes that occur at intersections, however, after adjusting for other significant factors (i.e., being at fault type of road, weather, lighting) the increased risk cannot be fully accounted for older drivers, nor does frailty. Thus, increased risk for older drivers could be due to their agerelated cognitive declines and possible differences in perceptions of intersections. The current study examines whether older drivers’ perceived complexity of intersections differed quantitatively and qualitatively from younger drivers’ perceived complexity of the same intersections. Coordinates of a random sample of intersections where at least one fatality occurred over a three-year period from the US Fatality Analysis Reporting System (FARS) were identified and Google Earth was used to extract still images of each intersection. The complexity of these intersection images were rated by a sample (N =38) of younger (age 18-35) and older drivers (age 65+). Inter-rater reliability for each group was calculated. In addition, individual intersection images with the largest and smallest age differences were qualitatively examined. Results suggest that older drivers view the complexity of intersections differently than younger drivers. Overall, older drivers were less reliable and scored nominally higher on average in their complexity ratings than younger drivers. Moreover, older drivers tended to rate rural or residential intersections as being more complex than younger drivers; whereas younger drivers tended to rate urban intersections as being more complex. Future work should account for these age differences in perceived intersection complexity

Glance behaviours when using an in-vehicle smart driving aid : a real-world, on-road driving study

In-vehicle information systems (IVIS) are commonplace in modern vehicles, from the initial satellite navigation and in-car infotainment systems, to the more recent driving related Smartphone applications. Investigating how drivers interact with such systems when driving is key to understanding what factors need to be considered in order to minimise distraction and workload issues while maintaining the benefits they provide. This study investigates the glance behaviours of drivers, assessed from video data, when using a smart driving Smartphone application (providing both eco-driving and safety feedback in real-time) in an on-road study over an extended period of time. Findings presented in this paper show that using the in-vehicle smart driving aid during real-world driving resulted in the drivers spending an average of 4.3% of their time looking at the system, at an average of 0.43 s per glance, with no glances of greater than 2 s, and accounting for 11.3% of the total glances made. This allocation of visual resource could be considered to be taken from ‘spare’ glances, defined by this study as to the road, but off-centre. Importantly glances to the mirrors, driving equipment and to the centre of the road did not reduce with the introduction of the IVIS in comparison to a control condition. In conclusion an ergonomically designed in-vehicle smart driving system providing feedback to the driver via an integrated and adaptive interface does not lead to visual distraction, with the task being integrated into normal driving

The Effects of Momentary Visual Disruption on Hazard Anticipation in Driving

Driver distraction is known to increase crashes, especially when the driver glances for especially long periods of time inside the vehicle. While it is clear that such glances increase risk for the driver when looking inside the vehicle, it is less clear how these glances disrupt the ongoing processing of information outside the vehicle once the eyes return to the road. The present study was aimed at exploring the effect of visual disruptions on the top-down processes that guide the detection and monitoring of hazards on the forward roadway. Using a driving simulator, twelve participants were monitored with an eye tracking system while they navigated various hazardous scenarios. Six participants were momentarily interrupted by a visual secondary task (simulating a glance inside the vehicle) prior to the hazard occurrence and six were not. Eye movement analyses show that interrupted drivers often failed to continue scanning for a hazard when their forward view reappeared. Implications of this study are discussed

Exploring Driver Responses to Unexpected and Expected Events Using Probabilistic Topic Models

Drivers’ expectations influence their responses to events in complex ways. In particular, covert and sustained hazards, like crosswinds, might require complex vehicle control adaptations. We investigated differences between drivers’ lateral responses in unexpected and expected (repeated) crosswind events using probabilistic topic modeling. First, each driver’s event-based steering wheel movements (angle and rate, 5 Hz) were transformed into symbolic words. Then, probabilistic topic modeling was used to discover patterns in the steering wheel movement data across the event conditions. Results indicate that drivers may make fewer abrupt steering wheel movements when they encounter unexpected crosswinds. On the contrary, drivers are more likely to make continuous faster steering corrections to compensate crosswinds when they are expected. The topic models also classify unexpected and expected crosswind events better than traditional models that use single aggregated values across events (maximum steering wheel angle and rate). These preliminary insights show an advantage for granular, time-series based analysis of driving data, and suggest a viable machinelearning based technique to conduct such investigations

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

The Effect of Time Constraints on Older and Younger Driver Decisions to Turn at Intersections Using a Modified Change Blindness Paradigm

After age 75, the risk of intersection accident involvement for older drivers increases for most intersection maneuvers. Failure to yield right-of-way and violation of traffic controls are common citations. Previous research has argued that age-related declines in attentional breadth and switching can discriminate between those who are and are not more likely to be in an accident. The present study examined the effect of time constraints on older and younger driver intersection decisions. It was expected that less time to decide, process and act upon intersection decisions would adversely affect older drivers more so than younger drivers. The change blindness or flicker paradigm was modified to address these questions (see, e.g., Rensink, et al., 1997). Typically, an image (A) is alternated with a modified image (A’) each for a short duration (250 ms) with a blank field or mask (80 ms) between A and A’. In the present study, a focus screen (or prime) that indicated the expected direction of travel (i.e., left, right, or straight) was added prior to the alternation of images. Forty-eight images were selected from 2500 intersection approaches in Calgary, Winnipeg and Montreal that were filmed using a digital camera during the day. Photoshop was used to create the A’ images by manipulating a variety of elements including pedestrians, vehicles, signs, and signals. The goal of the participant was to decide if the indicated direction of travel in the pair of intersection images was safe (press accelerator) or not (press brake). Sixteen younger (M = 22.3) and 16 older drivers (M = 73.6) drivers were screened for visual acuity, contrast sensitivity, and medication use. Length of image alternation was the primary independent variable (4 and 8 s). As expected, older drivers were more likely to miss intersection changes at shorter exposure durations than younger drivers. A number of qualitative probes were also collected that clearly illustrate the contextual demands of intersections on attention. The implications of the results for intersection design and older driver selective attention are discussed