Assessment of Sign Sheeting Decay

The primary objective of this research initiative is to establish a retroreflectivity assessment protocol for sign sheeting in order to meet federal requirements. While two methods, sign assessment or management, are allowable under the new ruling, this study will focus on assessment strategies. The MUTCD provides various options for assessment including visual nighttime inspection, measured sign retroreflectivity and expected sign life. For this study, retroreflectivity will be measured as a function of time. Decay curves will be generated with consideration to above referenced factors including sign orientation with reference to sun exposure, sheeting manufacturer, ASTM sign type designation, color and cleanliness. These will be compared to specified management strategies including blanket replacement and control signs to determine the most appropriate method. Currently, all field data collection efforts are complete which included establishing a sampling protocol, procurement of a retroreflectometer with GPS capability, evaluating the current retroreflectivity of 500 road signs in addition to photo and written documentation of corresponding variables such as sign type, sheeting type, age, location, and general condition. The final draft report has been generated and is currently under review.