6

Front of
License
Plate

00 0 / 0000/0/

Plate displayed at an angle to avoid
specular glare

Figure 1. Setup for Nighttime Legibility Experiment

7

Figure 2. Setup for Nighttime Conspicuity Experiment

Extended

Figure 3. License Plate Stand

10

Figure 4. Specimen Texas New Plates Used in the Conspicuity and
Legibility Experiments.

Figure 5. Specimen Texas Old Plates Used in the Conspicuity and
Legibility Experiments.

Figure 6. Specimen Arizona New Plates Used in the Conspicuity and
Legibility Experiments.

Figure 7. Specimen Arizona Old Plates Used in the Conspicuity and
Legibility Experiments.

19

Texas New

Texas Old

Arizona New

Arizona Old

Letters Only
Figure 8. Responses of 20 Subjects for Nighttime Legibility Experiment;
8 1.2 feet Legibility Distance; Three Letters Per Letter Group;
Dark Blue Letters on White Retro-reflective Background
for Texas Plates; White Retro-reflectiveLetters on Dark Red
Paint Background for Arizona Plates; Two Seconds Exposure Time;
Letter Height of 2.74" for Texas Plates, 2.86" for Arizona Plates;
Letter Width of 1.22"for Texas Plates, 1.23"for Arizona Plates;
Stroke Width of 0.33"for Texas Plates, 0.35"for Arizona Plates;
Letter Spacing of 0.39"for both Texas & Arizona Plates;
Center of License Plate held at a distance of 26"above ground;
Halogen H6054 HeadLarnps at a height of 24"above ground;
Low Beams; Total of 1440 Letter Presentations for Each License
Plate Type

Texas New

Texas Old

Arizona New

h n a Old

Numbers Only
Figure 9. Responses of 20 Subjects for Nighttime Legibility Experiment;
8 1.2 feet Legibility Distance; Three Numbers Per Number Group;
Dark Blue Numbers on White Retro-reflective Background
for Texas Plates; White Retro-reflective Numbers on Dark Red
Paint Background for Arizona Plates; Two Seconds Exposure Time;
Number Height of 2.74" for Texas Plates, 2.86" for Arizona Plates;
Number Width of 1.22" for Texas Plates, 1.23" for Arizona Plates;
Stroke Width of 0.33" for Texas Plates, 0.35" for Arizona Plates;
Number Spacing of 0.39" for both Texas & Arizona Plates;
Center of License Plate held at a distance of 26" above ground;
Halogen H6054 HeadLarnps at a height of 24"above ground;
Low Beams; Total of 1440 Number Presentations for Each License
Plate Type

21

Texas New

Texas Old

Arizona New

Arizona Old

Letters and Numbers (Characters)
Figure 10. Responses of 20 Subjects for Nighttime Legibility Experiment;
81.2 feet Legibility Distance; Three Letters and Three Numbers;
Dark Blue Characters on White Retrro-reflective Background
for Texas Plates; White Retro-reflective Characters on Dark Red
Paint Background for Arizona PIates; Two Seconds Exposure Time;
Character Height of 2.74" for Texas Plates, 2.86" for Arizona Plates;
Character Width of 1.22" for Texas Plates, 1.23" for Arizona Plates;
Stroke Width of 0.33" for Texas Plates, 0.35" for Arizona Plates;
Character Spacing of 0.39" for both Texas & Arizona Plates;
Center of License Plate held at a distance of 26" above ground;
Halogen H6054 HeadLarnps at a height of 24"above ground;
Low Beams; Total of 2880 Character Presentations for Each License
Plate Type.

23

0
Texas New

Texas Old

Arizona New

Arizona Old

Plates Displayed to the Left of the Experimental Car
Figure 11. Responses of 20 Subjects for Nighttime Conspicuity Experiment;
Dark Blue Letters on White Retro-reflective background for
Texas Plates; White Retro-reflective Letters on Dark Red Paint
Background for Arizona Plates; Two Seconds Exposure Time;
License Hates displayed at 20 feet to the Left of the Center Line
of the Experimental Car at a distance of 550 feet in front of the Car;
H6054 Lowbeams for Both the Experimental and the Opposing
Glare cars; Opposing Glare Car positioned at a distance 200 ft.
from the front of the Exwrimental car. with a Lateral Offset of
12 feet to the Left of thicenter Line ok the Experimental Car,
Total of 240 Presentations for each Plate Type.

24

Texas New

Texas Old

Arizona New

Arizona Old

Plates Displayed to the Right of the Experimental Car
Figure 12. Responses of 20 Subjects for Nighttime Conspicuity Experiment;
Dark Blue Letters on White Retro-reflective background for
Texas Plates; White Retro-reflectiveLetters on Dark Red Paint
Background for Arizona Plates; Two Seconds Exposure Time;
License Plates displayed at 20 feet to the Right of the Center Line
of the Experimental Car at a distance of 550 feet in front of the Car,
I36054 Lowbeams for Both the Experimental and the Opposing
Glare cars; Opposing Glare Car positioned at a distance 200 ft.
from the front of the Experimental car, with a Lateral Offset of
12 feet to the Left of the Center Line of the Experimental Car;
Total of 240 Presentations for each Plate Type.