The Effects of Commercial Electronic Variable Message Signs ...

APPENDIX A—EXPANDED TABLES
A.1 KEY FACTORS (INDEPENDENT VARIABLES)
Table 1. Expanded key factors (independent variables).
Variable Ref. # Advantages Disadvantages
1.0 Billboard
1.1 Location 8, 129,
38, 15,
44, 32
1.1.1 Lat./long.; GPS; mile
marker; survey location;
reference location; mobile
1.1.2 Distance from
roadway; setback
1.1.3 Sight distance; visual
occlusions; distance first
detected
1.1.4 Orientation; angle to
road; side of road; twosided
13, 53,
160
1.2 Display 144
1.2.1 Type: Conventional;
Digital; Tri-vision
1.2.2 Size; length; height;
visual angle; mounting
height
1.2.3 Resolution; dpi;
LEDs/in
1.2.4 Luminance; contrast
ratio; day/night settings
1.3 Dynamics 31
Important to define stimulus;
Easy to measure.
13, 53 Determines exposure time.
41
Likely to require travel
expenses.
Less important.
144 Less important.
125, 48 Digital type stands out. Tri-vision likely to disappear.
129, 32 Off-premise sizes somewhat
standard.
95, 48,
53
48, 53,
144
Crispness (sharpness) of
image important.
Brightness (luminance)
extremely important.
On-premise sizes variable.
Night setting may depend
upon background
illumination.