Age-related declines in car following performance under simulated fog conditions

Abstract

The present study examined age-related differences in car following performance when contrast of the driving scene was reduced by simulated fog. Older (mean age of 72.6) and younger (mean age of 21.1) drivers were presented with a car following scenario in a simulator in which a lead vehicle (LV) varied speed according to a sum of three sine wave functions. Drivers were shown an initial following distance of 18m and were asked to maintain headway distance by controlling speed to match changes in LV speed. Five simulated fog conditions were examined ranging from a no fog condition (contrast of 0.55) to a high fog condition (contrast of 0.03). Average LV speed varied across trials (40, 60, or 80 km/h). The results indicated age-related declines in car following performance for both headway distance and RMS (root mean square) error in matching speed. The greatest decline occurred at moderate speeds under the highest fog density condition, with older drivers maintaining a headway distance that was 21% closer than younger drivers. At higher speeds older drivers maintained a greater headway distance than younger drivers. These results suggest that older drivers may be at greater risk for a collision under high fog density and moderate speeds. KeywordsAging; driving; car following; fog; driving safety Driving simulators allow for the investigation and study of driving situations that are a potential safety risk to the driver. For example, driving simulation studies have examined the ability of drivers to detect impending collisions. Such an issue cannot be studied under real world conditions because of the potential accident risk to the driver should a collision occur. Thus, an important benefit of driving simulation studies is that it allows researchers to understand the perceptual or cognitive limitations of the driver by examining conditions that under real world driving that would introduce risk to the driver. The present study examined a driving scenario that is likely to introduce considerable risk to the driver under real world conditions---older drivers performing a car following task under foggy conditions. An important and consistent finding regarding driving safety is that accident risk increases for older driver populations (Langford & Koppel, 2006;Evans, 2004;Owsley et al., 1991). A detailed analysis of this issue was presented by Evans (2004) Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. FARS (Fatality Analysis Reporting System). The results indicated a steady increase in accident fatalities and rate of severe crashes for older drivers beginning at age 6...

Effects of fog, driver experience and gender on driving behavior on S-curved road segments

“…The presence of fog can reduce not only the visibility but also the visual field. Previous studies have confirmed that drivers tend to perform safety-related adaptations, such as reducing speed, to compensate for the insecurity arising from the limited visual field (Ni et al, 2010;Broughton et al, 2007). In this study, drivers reduced their speed significantly in the heavy fog condition on the straight road segment.…”

“…Fog as a type of inclement weather, has an enormous negative influence on drivers' visibility, which causes quite a change in driving behavior. Previous studies of driving behavior in fog have focused on drivers' car following performance (Broughton et al, 2007;Kang et al, 2008;Ni et al, 2010), collision avoidance performance (Ni et al, 2012;Mueller and Trick, 2012) and behavior/responses to road sign instructions (Hassan and Abdel-Aty, 2011;Trick et al, 2010). However, little research has investigated how drivers perform on roads with complex alignments such as S-curves when driving in fog.…”

Eye Movement Patterns and Driving Performance

“…One interesting topic for future research is to examine whether driving performance can improve by changing scan strategies. On a related issue, previous research found age-related decrement in performance in a car following task (Ni, Kang & Andersen, 2010). Another topic for future research is to examine whether age-related decrement in driving tasks could be predicted by an age-related difference in eye movement patterns, and whether we could improve older drivers' performance by training them to use a different scan strategy.…”

“…These tasks include steering control (Wallis, Chatziastros, Tresilian & Tomasevic, 2007), braking (Fajen, 2005), car following (Ni, Kang & Andersen, 2010), and collision detection (Ni & Andersen, 2008). Previous studies have shown that observers' ability to attend and process information in a visual scene is very limited (Rensink, 2002).…”

Driving Simulators for Occupational Therapy Screening, Assessment, and Intervention

“…Several research teams are examining older drivers (e.g. Freund & Colgrove, 2008;Freund et al, 2005aFreund et al, , 2005bHarvey et al, 1995;Hoffman & McDowd, 2010;Lee et al, 2002;Ni et al, 2010;Szlyk et al, 2002). In addition, researchers are using simulators to examine the impact of roadway design among older and younger drivers (e.g., Shechtman et al, 2007), or the impact of new technologies on different driving populations (e.g., Martin & Elefteriadou, 2010).…”