ASTM E3320-21 - Standard Test Method for Measurement of Retroreflective Pavement Marking Materials Using a Mobile Retroreflectometer Unit (MRU)

1.1 This test method covers measurement of the retroreflective properties of horizontal pavement marking materials containing retroreflecting optics, such as traffic stripes and surface symbols, using a mobile retroreflectometer unit that can be operated at traffic speed, mounted on a vehicle to measure the retroreflection at a prescribed geometry.

1.2 The entrance and observation angles of the MRU affect the readings. As specified by the European Committee for Standardization (CEN) and in Test Method E1710, the entrance and observation angles shall be 88.76° and 1.05°, respectively.

1.3 This test method is intended to be used for field measurement of pavement markings at traffic speed.

1.4 This test method is intended to be used for retroreflectivity measurement of dry pavement markings.

1.5 The 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.

1.6 This standard does not purport to address regulatory and safety regulations of the MRU and its use. It is the responsibility of the manufacturer to fulfill regulatory standards. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

1.7 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.