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Interpretations to Part 393 — Parts and accessories necessary for safe operation
Question 1: May windshields and side windows be tinted?
Guidance: Yes, as long as the light transmission is not restricted to less than 70 percent of normal (refer to the American Standards Association publication Z26.1-1966 and Z26.1a-1969).
Question 2: May a decal designed to comply with the periodic inspection documentation requirements of §396.17 be displayed on the windshields or side windows of a CMV?
Guidance: Yes, provided the decal is being used in lieu of an inspection report and is in compliance with §393.60(c).
Question 3: If a crack extended into the thickness of the glass at such an angle as to measure 1/4" or more, measuring from the top edge of the crack on the outside surface of the windshield to vertical line drawn through the windshield to the far edge of this angled crack on the inside of the windshield, would this constitute a crack of 1/4" or more in width as defined in §393.60(b)(2)?
Guidance: No. The crack, in order to fall outside the exception, would have to be a gap of 1/4" or more on the same surface of the windshield.