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Publication Number: FHWA-HRT-04-137
Date: December 2005

Enhanced Night Visibility Series, Volume VI: Phase II—Study 4: Visual Performance During Nighttime Driving in Fog

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LIST OF ACRONYMS AND ABBREVIATIONS


General Terms

AASHTO American Association of State Highway and Transportation Officials
ENV Enhanced Night Visibility
FHWA Federal Highway Administration
GPS Global Positioning System
ITS Intelligent Transportation Systems
SUV sport utility vehicle
UV ultraviolet
UV–A ultraviolet A (wavelength 315 to 400 nanometers)
VDOT Virginia Department of Transportation
VES vision enhancement system
VTRC Virginia Transportation Research Council

Vision Enhancement Systems

HLB halogen (i.e., tungsten-halogen) low beam
hybrid UV–A + HLB hybrid UV–A/visible output together with halogen low beam
five UV–A + HLB five UV–A headlamps together with halogen low beam
HLB–LP halogen low beam at a lower profile
HID high intensity discharge
IR–TIS infrared thermal imaging system

Statistical Terms

ANCOVA analysis of covariance
ANOVA analysis of variance
DF degrees of freedom
F value F-ratio
lsmean least-squares mean
MS mean square
P value statistical significance
SE standard error
SS sums of squares

Measurements

ft feet
h hours
km/h kilometers per hour
lx lux
m meter
mi/h miles per hour
W/cm² watts per square centimeter
µW/cm² microwatts per square centimeter

Stopping Distance

a deceleration rate
BRT braking reaction time
V velocity
d distance
g acceleration
f friction
G gradient
a deceleration rate

Contrast Sensitivity

cpd cycles per degree
PCLA percentage of contrast left eye line A (line A represents 1.5 cpd)
PCRA percentage of contrast right eye line A (line A represents 1.5 cpd)
PCLB percentage of contrast left eye line B (line B represents 3.0 cpd)
PCRB percentage of contrast right eye line B (line B represents 3.0 cpd)
PCLC percentage of contrast left eye line C (line C represents 6.0 cpd)
PCRC percentage of contrast right eye line C (line C represents 6.0 cpd)
PCLD percentage of contrast left eye line D (line D represents 12.0 cpd)
PCRD percentage of contrast right eye line D (line D represents 12.0 cpd)
PCLE percentage of contrast left eye line E (line E represents 18.0 cpd)
PCRE percentage of contrast right eye line E (line E represents 18.0 cpd)

 

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