Use this table to help determine the appropriate character size
to display upon viewing distance and the speed at which the viewer may be traveling.
Character
Size
Maximum Viewing
Distance
Inches
2
6
8
9
10
12
17
24
36
Feet
60
180
240
270
300
360
510
720
1080
Maximum Viewing Time in Seconds
5MPH
8.2
24.5
32.7
36.8
40.9
49.1
69.5
98.1
147.2
15MPH
2.7
8.2
10.9
12.3
13.6
16.4
23.2
32.7
49.1
25MPH
1.6
4.9
6.5
7.4
8.2
9.8
13.9
19.6
29.4
35MPH
1.2
3.5
4.7
5.3
5.8
7
9.9
14
21
45MPH
0.9
2.7
3.6
4.1
4.5
5.5
7.7
10.9
16.4
Green shaded areas represent an acceptable exposure time to view text messages.
55MPH
0.7
2.2
3
3.3
3.7
4.5
6.3
8.9
13.4
65MPH
0.6
1.9
2.5
2.8
3.1
3.8
5.3
7.5
11.3
75MPH
0.5
1.6
2.2
2.5
2.7
3.3
4.6
6.5
9.8