"Under low luminance conditions focal visual functions such as acuity, contrast sensitivity, and visual accommodation are degraded, and consequently the ability to recognize and identify objects is also reduced." (Source - Study conducted by Stacy Balk of Clemson University - 2007)
When working on making a vehicle more visible day and night, there are a few factors to consider. These are –
1. The colors of the conspicuity material to be used. (conspicuity simply means making something more visible)
2. The brightness or intensity of the material if reflective sheeting is to be used.
3. The Configuration of the tape or design. (Battenburg, Chevron Striping, Non Slanting Block Pattern, Message, etc..)
4. The Placement of the material on the vehicle. (location – rear, sides, front)
If you have been researching making a truck, van or automobile more visible you have probably come across the term “conspicuity”, "conspicuity tape" or "conspicuity design". The Cambridge Dictionary defines conspicuity as - " the state of being obvious to the eye or mind" or "standing out so as to be clearly visible." The ANSI/ISEA 107-2004 Standards describe conspicuity in more detail as: The characteristics of an object which determine the likelihood that it will come to the attention of an observer, especially in a complex environment which has competing objects.
The goal in marking fleet type vehicles is to make them more visible to the human eye which in turn increases response time for an approaching driver. According to , Ophthalmologist and refractive laser surgeon, the average person has a maximum field of vision of 180 degrees and a practical field of vision of 130 degree. (practical meaning that the field that both eyes detect together.) The very middle of this field or "central field of vision" is where we see things in great detail. This central vision field makes up only 5% of the total 130 degree field. Periphery vision makes up the rest.
Color by itself is not enough to locate or distinguish objects in our peripheral vision field. To detect objects in our peripheral we need contrast and luminance as well as color. Luminance contrast, color and stripe angles are three factors that affect conspicuity. These factors are normally the triggers that facilitate the recognition of an object.