The United States Sign Council (USSC) has released the details of a study conducted by The Larson Institute at Penn State University to determine the optimum brightness level of LED/EMC (Light Emitting Diode/Electronic Message Center) signs and displays under nighttime viewing. The research was approached with the idea of determining the appropriate level of brightness for motorists while driving at night so that they can both see and read the EMC signs yet at the same time the signs will not be over-bright or blinding to the viewer.
As explained in the research, the maximum luminance level of 710 to 760 nits at night for EMC
signs and displays was determined by testing a sampling of subjects at the Institute’s test track at
State College, Pennsylvania. The luminance level was varied and adjusted on the displays. (Note: Luminance refers to the brightness of the display at the face or surface of the sign and can be scientifically measured.)
The research was done from the perspective of the motorist and traffic safety. The traffic safety emphasis relates directly to governing entities who require a scientific basis for regulating local lighting levels. The recommendations made by the researchers are simple to understand by the average person and apply to situations in the real world.
A PDF copy of this research can be obtained on the USSC Web site at www.ussc.org. In addition, hard copies can also be ordered by calling 215/785-1922.
