Age and sex differences in simulated collision avoidance driving

Abstract

The ability to avoid collisions is essential for survival. Diminished avoidance abilities among older adults and those under age 12 may account for the disproportionately high number of older individuals and children involved in pedestrian-vehicle collisions (Choueiri, E. M, Choueiri, G. M, Choueiri, B. M., 1993); (Kingma, J., 1994); (Mathey, F.J.,1983). The growing number of traffic-related fatalities underscores the need to attain a better understanding of collision avoidance response skill changes across the life span and the need to develop systems for screening and assessing individual collision avoidance skills. The primary objective of the parent research was to develop a battery of tests and to examine the relationships between sensory, attention, cognition and motor skills with collision avoidance ability. The degree of skill exhibited by an individual in avoiding automobile collisions in the simulator is expected to be a useful indicator of his/her ability to perform other related complex vehicle-maneuvering tasks such as those required for automobile operation. The purpose of this thesis project was to develop a simulated collision avoidance testing (SCAT) apparatus and procedure and conduct a pilot study to examine the SCAT system sensitivity to age and sex differences of the vehicle operator, particularly with respect to intra-task manipulations of visibility, event uncertainty, and type of evasive maneuver. One hundred and six healthy functional volunteers served as participants. These volunteers have 19 (6-19 years) participants in the young group; 43 (20-59 years) participants in the adult group, and 44 (60-74+ years) participants in the senior group. Five sets of tasks were performed: (1) Simulated Collision Avoidance Task with overall measures including crash frequency and crash severity;(2) Sensory Integrity tests (vision, hearing, and health questionnaires); (3) Information Processing Tasks including reaction time and movement time tests; (4)Tasks of Everyday Attention and Cognition (TEAC): Visual Elevator Test (attention switching), Trails B Test (visual search), Telephone Directory Search Test (visual search), and Telephone Number Dialing Test (short-term memory); and (5) Movement Control Tasks: Grip Strength Test (strength), Balance Test (balance), Gross Motor (Fitts Tapping Test), Needle Threading Test (fine motor skill), Bow Tying Test (fine motor skill), and Tweezer Transfer Test (fine motor skill). The total time per test session was 90-120 minutes. Only the simulator results are presented in this thesis. Overall results for the SCAT showed significant differences in crash frequency ratio and crash severity as a function of age, sex, uncertainty and maneuver. Visibility was only marginally significant. The effects of age depended on level of task such that the senior group had a significantly higher crash frequency and severity than the other age groups for uncertain scenarios, while differences between other age groups were not significantly different There was an interaction of sex and maneuver in crash severity such that males performed worse than females. Females varied very little across maneuvers while males had progressively more fatal crashes from left to right to stop maneuvers. The stop maneuver had a significantly greater crash frequency than the left or right maneuvers. The right and stop maneuvers had a higher crash severity than the left maneuver for uncertain scenarios. Beneficial outcomes of this research for Hawaii and the nation may include improved medical screening and assessment batteries to aid licensing agencies, rehabilitation facilities, physicians, driver education specialists, law enforcement officers, families of unfit drivers, and all drivers on the road in identifying drivers who, for whatever reason, are unfit to drive without assistance. This research helps identify when collision avoidance abilities (and cognitive and motor function) reach maximal development, when they begin to decline, and the possibility of compensatory measures for recognized deficiencies. These findings are especially relevant to the identification of older persons at risk of auto accidents. Given the sensitivity to age and/or disability demonstrated by SCAT, these tasks may hold potential for screening candidates for driver's license renewal and for impaired driver rehabilitation in virtual reality ... risk free to the real world traffic. SCAT may comprise useful test battery elements for testing and predicting collision avoidance ability of potential drivers and for assessing an individual's fitness to drive thereby reducing traffic fatalities and extending the number of years of safe driving for motorists.