Minimum Retroreflectivity Levels for Blue and Brown Traffic Signs

Traffic Control Devices to include a standard for minimum levels of retroreflectivity that must be maintained for traffic signs. In 2003, the Federal Highway Administration published research recommendations for minimum maintained retroreflectivity levels for traffic signs. The recommendations included most sign types but did not include information signs, with blue backgrounds and white legends, and cultural resource signs, with brown backgrounds and white legends. The following document outlines the development of recommendations for the minimum maintained retroreflectivity levels for traffic signs with blue and brown backgrounds. The research described herein also included an investigation of the minimum maintained retroreflectivity levels required when signs are observed in conditions with glare from oncoming headlamps and in the presence of fixed roadway lighting. This report will be of interest to State and local agencies with responsibility for traffic signs and people involved in traffic sign maintenance