Louis Tijerina

Driver Distraction: Evaluation with Event Detection Paradigm

The effects of eight in-vehicle tasks on driver distraction were measured in a large, moving-base driving simulator. Forty-eight adults, ranging in age from 35 to 66, and 15 teenagers participated in the simulated drive. Hand-held and hands-free versions of phone dialing, voicemail retrieval, and incoming calls represented six of the eight tasks. Manual radio tuning and climate control adjustment were also included to allow comparison with tasks that have traditionally been present in vehicles. During the drive the participants were asked to respond to sudden movements in surrounding traffic. The driver’s ability to detect these sudden movements or events changed with the nature of the in-vehicle tasks that were being performed. Driving performance measures such as lane violations and heading error were also computed. The performance of the adult group was compared with the performance of the teenage drivers. Compared with the adults, the teens were found to choose unsafe following distances, have poor vehicle control skills, and be more prone to distraction from hand-held phone tasks.

Eye Glance Behavior of Van and Passenger Car Drivers During Lane Change Decision Phase

Data are presented on the eye glance behavior of passenger car and van drivers before the start of discretionary lane changes. Thirty-nine volunteers ranging from 20 to 60 years of age served as either van drivers (N = 19) or passenger car drivers (N = 20) in the study. Each driver used an instrumented vehicle and was accompanied by a ride-along observer in daylight and dry pavement conditions. The test route included driving on both public highways at 55 mph or more and city roads at 25 to 35 mph. A total of 549 lane changes (290 for vans, 259 for passenger cars) were analyzed in terms of driver eye glance behavior 10 s before the lane change start. Results indicated that for left-to-right lane changes, the probability of a glance to the center mirror was substantially higher than the probability of a glance to the right side mirror. For right-to-left lane changes, the probability of a glance to the center mirror was substantially less than that for rightward lane changes, and the probability of a glance to the left side mirror was appreciably higher than that for right side mirror use in rightward lane changes. These results held for both van and passenger car drivers. Except for a slightly higher probability of over-the-shoulder glances on city roads, these results hold for both highway and city street driving. These data should be factored into the design of lane change warning system displays and mirror systems.

Individual Differences and in-Vehicle Distraction While Driving: A Test Track Study and Psychometric Evaluation

The influence of individual differences on driver distraction was examined in this study. Sixteen (16) test participants were trained on destination entry procedures with four commercially available route guidance systems, as well as the dialing task on a commercially available wireless cellular telephone and on manually tuning an after-market car radio. The participants then drove an instrumented vehicle at approximately 45 mph on a 7.5 mile oval test track with very light traffic while concurrently engaging in various tasks with these devices. In-vehicle task completion time, average glance duration away from the road ahead, number of glances away from the road ahead, and number of lane exceedences were recorded. The participants were later given an automated battery of temporal visual perception and cognitive tasks. Performance on the test battery was then correlated to performance on the test track measures to determine the extent to which individual driver differences could account for observed performance differences. Analysis of these elementary test scores as predictors show low but consistent patterns of correlation to test-track performance measures.

Effects of Adaptive Lane Departure Warning System on Driver Response to a Surprise Event

A lane departure warning (LDW) system monitors the current lane position of a vehicle and presents a driver alert when one of the vehicles front tires crosses a threshold, for example, the nearest lane line. The primary intent of such warning systems is to prevent or mitigate road departures and related crashes caused by driver distraction or drowsiness. The present evaluation compared adaptive and nonadaptive versions of an LDW system. The adaptive version adapted to the drivers state, whereas the nonadaptive version did not. The adaptive LDW system alerted the driver only if a driver state monitor (DSM) indicated that the driver was looking away from the road ahead for 2 s or longer at about the time when a lane line was crossed. Forty volunteers drove a high-fidelity, moving-base driving simulator in a study to compare driver responses to a surprise lane departure when they used a nonadaptive LDW system and then an adaptive LDW system or vice versa. The results indicated that in the adaptive LDW mode, 13 subjects (34%) either experienced delayed activation of the LDW alert or received no LDW alert at all when they should have, primarily because of both the 2-s rule in the adaptive LDW algorithm and DSM registration issues. The adaptive LDW resulted in significantly larger lane excursions at the onset of the LDW alert compared with those that occurred in the non-adaptive LDW mode. These results highlight the dependence of the performance effects of adaptive systems on system hardware, algorithms, and algorithm parameters.

The Effects of a Scheduled Driver Engagement Strategy in Automated Driving

This simulator study investigated a driver engagement (DE) strategy designed to keep the driver-in-the-loop during automated driving in the face of two different types of secondary tasks. The method, first reported by Carsten et al. (2012), involved driving in fully automated driving mode for 6 minutes followed by 1 minute of manual driving, after which this fixed schedule was repeated several times throughout the drive. This scheduled strategy was compared to a reference condition in which different participants experienced continuous automated driving without interruptions. For each condition, some participants watched a video and others listened to the radio. All drives ended in automated driving mode with a surprise forward collision (FC) hazard to which the participant had to manually intervene. Compared to video watchers, radio listeners responded faster, looked to the road scene more, and they were more often looking forward at FC event onset. The DE strategy had no effect on radio listeners. In contrast, video watchers responded to the hazard more quickly with the scheduled strategy than without it. However, there was no reliable statistical difference between DE conditions in percent-eye-glance-time looking to the forward road scene during automated driving or in the number of drivers looking forward at FC event onset. Thus, the scheduled driver engagement strategy appears beneficial in the face of the visual (video) secondary task, but the reasons for this advantage remain to be determined.

Immediate Recall of Driver Warnings in Forward Collision Warning Scenarios

This paper describes driver recall performance for a forward collision warning (FCW) alert immediately after a critical lead vehicle braking event. A sample of 120 younger and older test participants, balanced by gender, participated in a study of alternative FCW alerts in the Ford Motor Company VIRTTEX driving simulator. A baseline group of participants received no FCW support. Each of the other participants experienced one and only one FCW alert type, visual, auditory, or both. Half of the participants who received an FCW alert had been given knowledge that such a system was in the test vehicle, and half of the participants had been told nothing. A digit-reading distraction task was presented repeatedly during the test drive. The last repetition of this task coincided with the lead vehicle braking event and FCW. Immediately after the event, test participants were asked if they had received a warning and, if so, what they recalled about it. Results were analyzed for those 93 warned test participants who interrupted the digit-reading task to respond to the FCW alert. Approximately 26% of these test participants did not remember receiving a warning at all. Only 58% of the test participants who recollected a warning could accurately recall its modality in all its details, although nearly 90% of those who received the combined audio and video warning recalled at least one of the modalities correctly. Those who received FCW information before the drive had significantly greater recollection than those who were not given any FCW a priori information. Age and gender differences were not statistically significant. The implications of these results are discussed.

Simulator Study of Effects of Alternative Distraction Mitigation Strategies in Driver Workload Manager

This simulator study examined a workload manager developed by Delphi Electronics for the SAVE-IT program and the effects of several different workload mitigation strategies on driver response to a surprise forward collision hazard. The strategies included no in-vehicle task or distraction (baseline); task allowed; task interrupted; and task denied. Forty-eight test participants (24 males and 24 females) between 35 and 55 years of age were randomly assigned in groups of 12 (balanced for gender) to each of the four conditions. Each participant then drove in the Ford VIRTTEX moving-base driving simulator on simulated urban and rural roads and was asked to perform various in-vehicle tasks. During a requested in-vehicle information system task, a vehicle parked on the side of the road would suddenly enter the travel lane, and the drivers response was assessed. Braking response to this critical event indicated no significant differences in mean brake response time as a function of type of mitigation strategy or gender. However, variability in driver responses was significantly less in the task denied condition as compared with the other conditions, possibly because drivers were sensitized to an increased driving demand. Three of 12 test participants in the task interrupted condition showed relatively large brake reaction times attributable to long delays between initial foot motion and braking onset. This delay may indicate an additional delay associated with processing the task interruption and the forward collision warning event itself. Recommendations are provided for further research and for mitigation and driver alerting on the basis of a workload managers assessment of the driving situation.

Ford’s Approach to Managing Driver Attention: SYNC and MyFord Touch

SYNC and MyFord Touch represent the new direction in automotive human-machine interface (HMI) for Ford Motor Company. Improving driver focus was one of the most critical aspects in the development of the new HMI. This article describes the approach used in development to ensure that driver attention would be improved with this new system. This approach includes research, technology, requirements, and education. The research that was conducted and used, the technology and associated benefits, and the requirements that were followed during the development of the new system are summarized.

Eye Glance and Head Turn Correspondence during Secondary Task Performance in Simulator Driving

This paper and its findings serve as a fundamental characterization of the interaction between the head and eye as a function of task demand and duration while driving. These findings have potential use in future vehicle active safety, and the design of driver assistance and/or HMI systems and features. Our findings show that head position and eye-point-of regard for certain task locations have dependence and may be suited to characterize task engagement while driving.

Preliminary Evaluation of the Proposed Sae J2364 15-Second Rule for Accessibility of Route Navigation System Functions while Driving

A test-track study was conducted to assess the diagnostic properties of SAE J2364, the so called 15-second rule. Ten (10) drivers between the ages of 55 and 69 completed tasks both in a parked vehicle (statically) and while driving (dynamically). They engaged in 15 different tasks, including various destination entry tasks, with four commercially available route guidance systems, manual cell phone dialing, manually tuning an after-market in-dash radio to specific AM and FM stations, and adjusting the HVAC controls in the test vehicle. Simple linear regression models to predict dynamic task completion time from static task completion time revealed an R2 = 0.39. A model to predict number of lane exceedences from static completion time had an R2 = 0.27. A regression equation to predict lane exceedences from dynamic completion time had an R2 = 0.43. Classification performance of the 15-second rule was analyzed using criteria based on “degraded performance” defined as 2 or more drivers exhibiting 2 or more lane departures during task execution on the 7.5 mile test track. Where 2 or more drivers had static completion times of greater than approximately 15 seconds, the task would fail the test. In terms of True Positives, all route navigation system destination entry tasks that required visual-manual methods both failed the 15-second rule and were associated with disrupted lanekeeping. In terms of False Negatives, tuning the Clarion after-market radio took less than about 15 seconds for static completion yet was associated with above-threshold disruptions of lanekeeping on the test track. In terms of True Negatives, the HVAC adjustment was the only task which was both completed in less than 15 seconds statically and had no appreciable effect on lanekeeping during the test track trials. Finally, five of the 15 tasks took longer than 15 seconds to complete in a parked vehicle (i.e., statically) yet were not associated with significant disruptions in lanekeeping on the test track. The results of this preliminary assessment suggest that the 15-second rule, as implemented, has diagnostic sensitivity close to chance guessing. It identified most, though not all, demanding interactions at the expense of numerous false positives. These preliminary findings, together with the observation that the 15-second rule is, in itself, not diagnostic with regard to the locus of a driver distraction effects, suggest that opportunities for improvement or enhancement should be pursued. Recommendations are discussed.