Search

Introduction: Vision standards for driving are typically based on visual acuity, despite evidence that it is a poor predictor of driving safety and performance. However, visual motion perception is potentially relevant for driving, as the vehicle and surroundings are in motion. This study explored whether tests of central and mid-peripheral motion perception better predict performance on a hazard perception test (HPT), which is related to driving performance and crash risk, than visual acuity. Additionally, we explored whether age influences these associations, as healthy ageing impairs performance on some motion sensitivity tests., Methods: Sixty-five visually healthy drivers (35 younger, mean age: 25.5; SD 4.3 years; 30 older adults, mean age: 71.0; SD 5.4 years) underwent a computer-based HPT, plus four different motion sensitivity tests both centrally and at 15° eccentricity. Motion tests included minimum displacement to identify motion direction (D min ), contrast detection threshold for a drifting Gabor (motion contrast), coherence threshold for a translational global motion stimulus and direction discrimination for a biological motion stimulus in the presence of noise., Results: Overall, HPT reaction times were not significantly different between age groups (p = 0.40) nor were maximum HPT reaction times (p = 0.34). HPT response time was associated with motion contrast and D min centrally (r = 0.30, p = 0.02 and r = 0.28, p = 0.02, respectively) and with D min peripherally (r = 0.34, p = 0.005); these associations were not affected by age group. There was no significant association between binocular visual acuity and HPT response times (r = 0.02, p = 0.29)., Conclusions: Some measures of motion sensitivity in central and mid-peripheral vision were associated with HPT response times, whereas binocular visual acuity was not. Peripheral testing did not show an advantage over central testing for visually healthy older drivers. Our findings add to the growing body of evidence that the ability to detect small motion changes may have potential to identify unsafe road users., (© 2023 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Purpose: Drivers' responses and eye movements were assessed as they approached pedestrians at night in order to explore the relative conspicuity benefits of different configurations of retroreflective markings., Methods: Eye movements were recorded using an ASL Mobile Eye (Applied Science Technologies, www.asleyetracking.com) from 14 young licensed drivers (M = 24.1 ± 6.4 years) as they drove along a closed-road circuit at night. At two locations, pedestrians walked in place facing either towards or away from the road. Pedestrians wore black clothing with a standard retroreflective vest either alone or with additional retroreflective markers positioned in a configuration conveying biological motion (biomotion). Drivers responded when they recognised that a pedestrian was present and again when they identified the direction the pedestrian was facing., Results: Drivers recognised pedestrians from a significantly greater distance (p < 0.05) when the pedestrian's clothing included the biomotion configuration (319.1 m) than when the biomotion markings were absent (184.5 m). Further, the drivers recognised the direction that the pedestrian faced from a longer distance when biomotion markings were present (215.4 m vs 95.6 m). Eye movement data suggested that the biomotion configuration attracted drivers' attention significantly sooner than the vest (time to first fixation: 1.1 vs 3.5 s), that drivers fixated on pedestrians wearing biomotion for significantly less time prior to responding (3.4 s vs 6.1 s), and the time to first recognise a pedestrian was approximately half that for biomotion compared to vest (6.4 vs 13.9 s)., Conclusion: Adding biomotion reflectors to the vest facilitated earlier recognition of pedestrians and faster identification of the direction that the pedestrian faced. These findings confirm that the conspicuity advantages of biomotion configurations on pedestrians at night result in part from drivers fixating pedestrians earlier and more efficiently., (© 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.)

Purpose: Age-related changes in motion sensitivity have been found to relate to reductions in various indices of driving performance and safety. The aim of this study was to investigate the basis of this relationship in terms of determining which aspects of motion perception are most relevant to driving., Methods: Participants included 61 regular drivers (age range 22-87 years). Visual performance was measured binocularly. Measures included visual acuity, contrast sensitivity and motion sensitivity assessed using four different approaches: (1) threshold minimum drift rate for a drifting Gabor patch, (2) Dmin from a random dot display, (3) threshold coherence from a random dot display, and (4) threshold drift rate for a second-order (contrast modulated) sinusoidal grating. Participants then completed the Hazard Perception Test (HPT) in which they were required to identify moving hazards in videos of real driving scenes, and also a Direction of Heading task (DOH) in which they identified deviations from normal lane keeping in brief videos of driving filmed from the interior of a vehicle., Results: In bivariate correlation analyses, all motion sensitivity measures significantly declined with age. Motion coherence thresholds, and minimum drift rate threshold for the first-order stimulus (Gabor patch) both significantly predicted HPT performance even after controlling for age, visual acuity and contrast sensitivity. Bootstrap mediation analysis showed that individual differences in DOH accuracy partly explained these relationships, where those individuals with poorer motion sensitivity on the coherence and Gabor tests showed decreased ability to perceive deviations in motion in the driving videos, which related in turn to their ability to detect the moving hazards., Conclusions: The ability to detect subtle movements in the driving environment (as determined by the DOH task) may be an important contributor to effective hazard perception, and is associated with age, and an individuals' performance on tests of motion sensitivity. The locus of the processing deficits appears to lie in first-order, rather than second-order motion pathways., (© 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.)

Purpose: To quantify the effects of driver age on night-time pedestrian conspicuity, and to determine whether individual differences in visual performance can predict drivers' ability to recognise pedestrians at night., Methods: Participants were 32 visually normal drivers (20 younger: M = 24.4 years ± 6.4 years; 12 older: M = 72.0 years ± 5.0 years). Visual performance was measured in a laboratory-based testing session including visual acuity, contrast sensitivity, motion sensitivity and the useful field of view. Night-time pedestrian recognition distances were recorded while participants drove an instrumented vehicle along a closed road course at night; to increase the workload of drivers, auditory and visual distracter tasks were presented for some of the laps. Pedestrians walked in place, sideways to the oncoming vehicles, and wore either a standard high visibility reflective vest or reflective tape positioned on the movable joints (biological motion)., Results: Driver age and pedestrian clothing significantly (p < 0.05) affected the distance at which the drivers first responded to the pedestrians. Older drivers recognised pedestrians at approximately half the distance of the younger drivers and pedestrians were recognised more often and at longer distances when they wore a biological motion reflective clothing configuration than when they wore a reflective vest. Motion sensitivity was an independent predictor of pedestrian recognition distance, even when controlling for driver age., Conclusions: The night-time pedestrian recognition capacity of older drivers was significantly worse than that of younger drivers. The distance at which drivers first recognised pedestrians at night was best predicted by a test of motion sensitivity., (© 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.)