Retroreflectometers and Highway Safety Instruments
Starting with the publishing of the 2009 edition of the Manual on Uniform Traffic Control Devices (MUTCD) agencies have been scrambling to understand what they need to do to be compliant with the rules governing retroreflectivity minimums of their traffic signs in use. Simply put, the retroreflectivity requirements state that every agency with signs under [...]
Laboratory measurement of retroreflective materials is accomplished using tightly controlled procedures. These procedures are defined and controlled by the American Society for Testing of Materials (ASTM). The ASTM procedures for laboratory measurements require the use of a tungsten lamp operated at a correlated color temperature of 2855.6 degrees Kelvin. The spectral power distribution of a [...]
Coefficient of Retroreflected Luminance (RL ) is the most commonly used measurement of retroreflectance in highway marking. RL is the ratio of the luminance (L) of a surface to the normal illuminance (E) on the surface. In the laboratory this definition works well with testing procedures. This excerpt is taken from the RoadVista Guide to [...]
Starting with the publishing of the 2009 edition of the Manual on Uniform Traffic Control Devices (MUTCD) agencies have been scrambling to understand what they need to do to be compliant with the rules governing … [Read More...]
