Abstract
Purpose :
Strict regulations to obtain or renew a driving license are still weak in most countries. Moreover, when a visual criteria is included in the requirements, the tests are usually restricted to visual acuity assessment. Nevertheless, resuming driving behavior into one unique score might lead to neglect important components of driving abilities. In the present study, we proposed to build a global score considering a set of important driving components.
Methods :
51 licensed drivers with normal vision between the ages of 71 and 86 were recruited. They performed a rural scenario within a driving simulator (9 driving measures), a visual acuity, stereoscopic acuity and visual field tests as well as a perceptual-cognitive test known as the 3-Dimensional Multiple Object Tracking task (3D-MOT). Based on these measures, we computed the area of a radar chart visualization and built a global index we called Driver’s Safety Index (DSI), thought to represent the amount of limitations an individual must deal with to effectively control a vehicle. Through bivariate correlations, we compared the efficiency of DSI and visual acuity in characterizing driving behaviors.
Results :
The results evidenced strong correlations between the perceptual-cognitive score and several driving measures [crashes (r= -.31; p< .001); standard deviation of lane position (SDLP; r= -.26; p= .005)] as well as with some visual measures [stereoscopic vision (r= -.44; p= .001) and to a lesser extent with visual acuity (r= -.25; p= .07)]. More importantly, visual acuity was not correlated with popular measures of driving fitness such as the SDLP (r= .04; p= .8) and the mean speed naturally adopted (r= -.03; p= .8) whereas DSI was correlated with these same measures [SDLP (r= -.33; p= .02); mean speed (r= .3; p= .03)].
Conclusions :
The present study evidences that the DSI is efficient to easily characterize driving behaviors and to pin down the kind of limitations an individual must deal with to effectively control a vehicle. The present investigation paves the way toward an intended index, which might be translated into licensing policies. However, its approval will require further studies to assess the relevance of the DSI in actual on-road driving or individuals with uncorrected vision.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.