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It is important for large trailers to be outlined with retroreflective tape to make them more conspicuous in roadway environments with diminished ambient lighting. Retroreflective material is also utilized on signs as well as clothing to improve their conspicuity. As used conspicuity tape does not perform at the same level as clean and new tape. Hence, there is a need for visibility testing of retroreflective materials with degraded or reduced effectiveness. In an effort to control the coefficient of retroreflection (RA). A methodology that uniformly obscured parts of the retroreflective materials was developed. Validation testing of this procedure was conducted using glass bead sheeting, as well as microscopic prismatic sheeting. The results from the study showed that, by uniformly obscuring parts of the tape, RA is approximately a linear function of the area exposed to the viewer. Thus, the overall perceived brightness and coefficient of retroreflection readings were reduced.

Modeling retroreflective material in a three-dimensional computer modeling and Physically Based Rendering (PBR) engine is extremely difficult without fully understanding the physics behind how the light rays interact and behave with the retroreflective materials. Without the proper engineering and physics understanding, incorrect, inaccurate and unfair animations can be created that attempt to show the visibility of retroreflective materials. In this paper we will discuss the engineering and physics of retroreflective materials and how light interacts with these materials. We will also describe how to incorporate the engineering and science of retroreflective materials into a PBR engine to create a fair and accurate light simulation displaying the visibility of the retroreflective materials.

Mapping a light source, any light source, is of broad interest to accident reconstructionists, human factors professionals and lighting experts. Such mappings are useful for a variety of purposes, including determining the effectiveness and appropriateness of lighting installations, and performing visibility analyses for accident case studies. Currently, mapping a light source can be achieved with several different methods. One such method is to use an illuminance meter and physically measure each point of interest on the roadway. Another method utilizes a goniometer to measure the luminous intensity distribution, this is a near-field measurement. Both methods require significant time and the goniometric method requires extensive equipment in a lab. A third method measures illumination distribution in the far-field using a colorimeter or photometer.

Vision is the primary sense used to navigate through this world when driving, walking, biking, or performing most tasks. and thus visibility is a critical concern in the design of roadways, pathways, vehicles, buildings, etc. and the investigation of accidents. In order to assess visibility, the accident scene can be documented under similar conditions. Geometric and photometric measurements can be taken for later analysis. Calibrated photographs or video of a recreated scene can be captured to illustrate the visibility at a later time. This process can often require significant coordination of the physical features at the scene. It can be difficult to precisely control the motion and timing of moving features such as pedestrians and vehicles. The result is fixed in that you capture specific scenarios with specific conditions with the selected field of view and perspective of the cameras used.