STV Grid

STV (Small Target Visibility) measures the visibility level of small targets as they are seen against the pavement background. The following factors are considered: target luminance, background luminance, adaptation level and disability glare.

The Visibility Levels (VL) are computed at the same points as the pavement luminance. The Observer position is located 83.07 meters back from each point. The weighted average of the target visibility levels is reported as the STV.