This part of EN 12676 specifies the characteristics of an anti-glare system in terms of its optical effectiveness and of the mechanical performance of its elements. It gives a method for the determination of the optical performance of anti-glare systems by calculation. Requirements and recommendations for the design of anti-glare systems to minimize maintenance are also given. This part of EN 12676 does not apply to: - types of anti-glare systems other than those attached to safety barriers; - regulatory characteristics which might be required to ensure that anti-glare systems are compatible with road signs; - specific requirements resulting from extreme en