ASTM_F_923_-_94.pdf

Designation:F 923 94a00Standard Guide toProperties of High Visibility Materials Used to ImproveIndividual Safety1This standard is issued under the fixed designation F 923;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.INTRODUCTIONFor many years the problem of pedestrianmotor vehicle collisions has been a major one in theUnited States and the rest of the world.In the U.S.,in the last three years for which data are available(19881990),there have been on the average about 8200 pedestrian fatalities per year,of which about54%occurred at night(1).2In addition,over 100 000 pedestrians were injured by motor vehicles eachyear(2).Lack of adequate visibility and conspicuity of pedestrians at night and during the day is consideredto play a direct role in many of these accidents.An investigation of pedestrian accidents lists thefollowing six driver and pedestrian actions necessary for safe travel:search,detection,evaluation,decision,human action,and vehicle action(3).Research shows that pedestrians typically overestimate their visibility(4).Since the averagepedestrian is not likely to be able to determine means for establishing adequate visibility,guidelinesare needed to improve visibility and conspicuity of pedestrians.Guidelines and,in fact,standards(5,6)have been provided for other road users(for example,trucks,passenger cars,motorcycles,andbicycles)in an attempt to meet visibility needs,but not for pedestrians.This guide provides generalprinciples for the enhancement of pedestrian visibility both at night and during the day.Theseprinciples also generally apply to anyone else exposed to motor vehicles,including constructionworkers,airport workers,bicyclists,and motorcyclists.1.Scope1.1 This guide covers the physical principles and variables involved in the performance and selection of high visibility materialsfor individual safety.1.2 It is the purpose of this guide to examine the principles on which future standards relating to individual safety may be used.However,this guide does not set minimum standards for the properties of high visibility materials.1.3 In reviewing the principles contained in this guide,it must be remembered that there are numerous factors adverselyaffecting visibility and safety(for example,rain,snow,road grime,alcohol,advanced age,drugs,fatigue,inattention,headlampmisalignment or breakage)that must be taken into account when dealing with actual safety requirements.1.4 This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2.Referenced Documents2.1 ASTM Standards:1This guide is under the jurisdiction of ASTM Committee E-12 on Color and Appearance and is the direct responsibility of Subcommittee E12.08 on High VisibilityMaterials for Individual Safety.Current edition approved May 15,1994.Dec.10,2000.Published July 1994.February 2001.Originally published as F 923 85.Last previous edition F 923 94a.2The boldface numbers in parentheses refer to the list of references at the end of this standard.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version.Becauseit may not be technically possible to adequately depict all changes accurately,ASTM recommends that users consult prior editions as appropriate.In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.D 1535 Test Method 1535 Practice for Specifying Color by the Munsell System3D 2244 Test Method for Calculation of Color Differences from Instrumentally Measured Color Coordinates3E 284 Terminology of Appearance3E 308 Test Method 308 Practice for Computing the Colors of Objects by Using the CIE System3E 808 Practice for Describing Retroreflection3E 809 Practice for Measuring Photometric Characteristics of Retroreflectors32.2Other Standards:CIE S002 Colorimetric Observers4SAE J579c Sealed Beam Headlamp Units for Motor Vehicles53.Terminology3.1DefinitionsTerms and definitions in Terminology E 284 and Practice E 808 are applicable to this guide.3.1.1 brightness,nattribute of a visual perception according to which an area appears to emit more or less light.3.1.2 conspicuity,nthe characteristics of an object that determine the likelihood that it will come to the attention of anobserver.3.1.3 divergence angle,nuse the preferred term,observation angle.3.1.4 entrance angle,b,n in retroreflection,the angle between the illu