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Publication Number: FHWA-HRT-04-134
Date: December 2005

Enhanced Night Visibility Series, Volume III: Phase II—Study 1: Visual Performance During Nighttime Driving in Clear Weather

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LIST OF ACRONYMS AND ABBREVIATIONS

General Terms

AASHTO American Association of State Highway and Transportation Officials
ENV Enhanced Night Visibility
VES vision enhancement system
SUV sport utility vehicle
UV–A ultraviolet A (wavelength 315 to 400 nanometers)

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
three UV–A + HLB three UV–A headlamps 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
HHB halogen high beam
HOH high output halogen
HID high intensity discharge
hybrid UV–A + HID hybrid UV–A/visible output together with high intensity discharge
three UV–A + HID three UV–A headlamps together with high intensity discharge
five UV–A + HID five UV–A headlamps together with high intensity discharge
IR–TIS infrared thermal imaging system

Statistical Terms

ANOVA analysis of variance
DF degrees of freedom
F value F-ratio
MS mean square
p value statistical significance
SE standard error
SS sums of squares

Measurements

cm centimeters
ft feet
h hours
m meters
mi/h miles per hour
km/h kilometers per hour
s seconds
W/cm² watts per square centimeter
µW/cm² microwatts per square centimeter

Stopping Distance

BRT braking reaction time
V velocity
d distance
dBD braking 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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