The effects of severe visual challenges on steering performance in visually healthy young drivers.
OBJECTIVE
Two experiments explored the extent to which induced blur, reduced luminance, and reduced visual fields affect drivers' steering performance in a driving simulator.


METHODS
In experiment 1, ten young participants (M = 21.2 years) drove at approximately 89 km/h (55 mph) along a curvy roadway while being exposed to blur (0 to + 10 D), luminance (0.003 to 16.7 cd/m), and visual field (1.7 and 150 degrees) manipulations. In experiment 2, a new group of ten young participants (M = 18.5 years) drove while exposed to seven visual field sizes (1.7 to 150 degrees).


RESULTS
Steering was sensitive to a reduced field size but not to the blur and luminance challenges. Acuity, on the other hand, was sensitive to the blur and luminance challenges but not to reduced field size.


CONCLUSIONS
In healthy young drivers, steering performance is remarkably robust to severe blur and to extremely low luminances. These results support a key element of the selective degradation hypothesis advanced by Leibowitz and colleagues--that steering abilities are preserved at night even when the ability to recognize objects and hazards is not. Additional research should address the other element of this hypothesis--that drivers fail to appreciate the extent to which their visual abilities are degraded at night.
Brooks
Johnell O
JO
Psychology Department, Clemson University, Clemson, South Carolina 29634-1355, USA. jobrook@clemson.edu
Tyrrell
Richard A
RA
Frank
Talissa A
TA
D000328:Adult; D000704:Analysis of Variance; D001334:Automobile Driving / Q000592:standards*; D015350:Contrast Sensitivity; D006801:Humans; D008027:Light; D011597:Psychomotor Performance; D012720:Severity of Illness Index; D014786:Vision Disorders / Q000503:physiopathology* / Q000523:psychology*; D014792:Visual Acuity; D014794:Visual Fields