Interpretation ID: nht76-2.28
DATE: 10/08/76
FROM: AUTHOR UNAVAILABLE; S. P. Wood for F. Berndt; NHTSA
TO: American Honda Motor Co., Inc.
TITLE: FMVSS INTERPRETATION
TEXT: This is in reply to your letter of September 23, 1976, asking for an interpretation of the spacing requirements for motorcycle turn signal lamps specified in Table IV of Motor Vehicle Safety Standard No. 108.
Standard No. 108 requires that motorcycle turn signal lamps be located so that their edges are at least 4 inches from the edge of the headlamps (on the front) and tail or stop lamps (on the rear). You have asked for confirmation "that the minimum separation distance is measured between the edges of the illuminated lenses of the respective lamps on a line passing through each lamp . . . rather than being measured on a horizontal line between two planes touching the edges of the illuminated lenses".
This will confirm your interpretation that the minimum separation distance is to be measured at the point where the edges of the two lamps are closest to each other.