ASTM D8424-21

5.1?The nighttime retroreflective properties of pavement markings are known to improve driving safety. Retroreflective composite optics have been developed to improve retroreflectivity in dry and rainy wet conditions. For customers purchasing these materials its important to verify the consistency and performance. This guide provides a set of laboratory procedures which can be selected individually or together to evaluate lot-to-lot consistency of composite optics of the same type and manufacturer. These are not in-service performance procedures and dont necessarily predict in-service performance.

1.1?This guide presents a series of options for evaluating lot-to-lot consistency of retroreflective composite optics of the same type and form from the same manufacturer and does not recommend any specific course of action to be taken. This guide is meant to increase the awareness of information and approaches and is not meant to recommend any specific course of action per ASTMs Form and Style for ASTM Standards definition for a Guide.

1.2?UnitsThe values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

1.3?This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.