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原文传递 National Calibration Facility for Retroreflective Traffic Control Materials.

题名：	National Calibration Facility for Retroreflective Traffic Control Materials.
作者：	miller, c. c. heimer, t. early, e.
关键词：	nightime visibility, safety, pavement marking, standards, research, accuracy
摘要：	Retroreflective traffic control devices are widely used for nighttime visibility and safety. Congress has directed the U.S. Department of Transportation to establish 'a standard for a minimum level of retroreflectivity that must be maintained for pavement markings and signs which apply to all roads open to public travel.' Establishing a national standard for minimum levels of retroreflectivity will require accurate methods to measure retroreflectivity. Instruments are commercially available for measuring the retroreflectivity of signs and markings, and documented standards establish procedures for such measurements. However, there can be significant variability among instruments measuring the same object, and the standards do not ensure accuracy of the instruments. There are currently no traceable methods in the United States to determine the accuracy of measurements, because national calibration standards for retroreflectivity do not exist. This research is intended to develop dedicated reference instrumentation to provide national calibration standards for retroreflectivity, thereby improving the accuracy of measurements made by other instruments. The instrumentation shall have the widest possible dynamic range to measure current and anticipated levels of performance of retroreflective traffic control materials. The reference instrumentation will use modern techniques to perform calibrations in compliance with all relevant standards. This instrumentation will have sufficient flexibility to measure spectral and luminous quantities of retroreflective traffic control materials over the full range of angles and will have the best possible accuracy. / NOTE: Interim handbook. / Supplementary Notes: See also PB2007-106710 and Phase 1, PB2003-101573. Prepared in cooperation with National Inst. of Standards and Technology, Gaithersburg, MD. Sponsored by American Association of State Highway and Transportation Officials, Washington, DC. and Federal Highway Administration, Washington, DC. / Availability Note: Product reproduced from digital image. Order this product from NTIS by: phone at 1-800-553-NTIS (U.S. customers); (703)605-6000 (other countries); fax at (703)605-6900; and email at orders@ntis.gov. NTIS is located at 5285 Port Royal Road, Springfield, VA, 22161, USA.
总页数：	u0711；154p
报告类型：	科技报告