Glare and Nighttime
Roadway Visibility
Douglas Mace
[email protected]
John Vanderlofske
[email protected]
www.lrc.rpi.edu
Causes of Glare During
Night Driving
Illuminance from the glare source
Headlights, mirrors, reflective surfaces
Glare angle
Interaction of beam pattern, distance and
angle
Driver age
Background luminance
Area of glare source and luminance
Variables that Determine
Visibility
Size
Contrast
Adaptation
Glare
Countermeasures That
Indirectly Minimize Glare
Fixed Roadway Lighting
Restricted Night Driving
Corrective Lenses and Surgery
Headlamp Area
Ultraviolet Headlights
Restricted Night Driving
Absence of valid vision test
Reduced mobility
Self selection
Mitigation of Headlight
Glare
5% reduction
with lighting
350
Detection Distance
16% reduction in
detection
distance without
lighting
300
250
325
309
243
204
200
150
100
no light
with light
50
0
No glare
glare
Glare Condition
Mitigation of Headlight
Glare
Significant loss in
detection distance for
no light (16%) and low
luminance (10%)
Non-significant loss in
detection distance for
medium luminance
(2.2%) and high
luminance (1.6%)
Detectin distance
by luminance level - Older Drivers
400
350
360
354
300
293
286
250
234
222
200
211
188
150
100
No glare
glare
Glare Condition
no light
low
medium
high