SUMMARY: NHTSA is issuing this NPRM as part of the agency's ongoing effort to harmonize vehicle safety standards under the Economic Commission for Europe 1998 Agreement. Following a vote in favor of establishing a global technical regulation (GTR) on automotive glazing@ we are initiating the process for considering adoption of the GTR. The changes proposed in this NPRM to the Federal motor vehicle safety standard on glazing materials would better harmonize U.S. regulatory requirements with those of other industrialized countries@ by modernizing the test procedures for tempered glass@ laminated glass@ and glass-plastic glazing used in front and rear windshields and side windows. We believe that most of the changes in this proposal would constitute minor amendments that would harmonize differing measurements and performance requirements for similar test procedures. Many of the tests in the GTR are substantially similar to tests currently included in Federal Motor Vehicle Safety Standard No. 205. We believe that the most significant improvements proposed in the GTR include an upgraded fragmentation test designed to better test the tempering of curved tempered glass@ and a new procedure for testing an optical property of the windshield at the angle of installation@ to better reflect real world driving conditions than the current procedure used in Standard No. 205. Comments are requested on whether these and the other provisions of the GTR are suited for adoption into the Federal glazing standard.