Development of a device to evaluate the retro-reflective performance of pavement marking materials (FHWA-81-2) 2135

Abstract

The objective of this research study was to investigate possible techniques for measuring the brightness of the retro-reflective pavement markings on a highway surface. The measurements were to be made during daylight hours and from a moving vehicle. A practical field device, or instrument, was then to be designed and developed. During the course of the project, one major change was made in the objective. This was to measure the contrast of the stripe to its background rather than stripe luminance only. A bench prototype of the optical system and the servo controlled tracking system has been constructed and tested in the laboratory. This report discusses the system requirements, the design approaches considered, the prototype tracking system and the proposed design of the complete device.