Interpretation ID: aiam1697
Commander
Engineering Section
Department of California Highway Patrol
P. O. Box 898
Sacramento
CA
95804;
Dear Mr. Heath: Your letters of November 6, 1974 and November 19, 1974 to Jim Brelan of Denver, Colorado (copies enclosed) have come to our attention and we have some comments to make on them.; The two letters in question concern the use of multiple front, middle and rear side marker lamps. Your letter of November 6 states that 'your intermediate side marker lamps at non-specified locations are not permitted and must be removed.' With respect to your letter of November 19, it is your view that an array of five side marker lamps 'installed at the top and bottom of each side' of a trailer over 30 feet in length is improper and that 'two of the top and two of the bottom ones on each side must be removed.' The single lamp remaining at the mid point and at each end of the vehicle 'shall be located at or near the front, center and rear on each side at the top and bottom or top or bottom.' You conclude that 'This requirement is not only a California regulation but is also in Federal Motor Vehicle Safety Standard No. 108.'; The letters are incorrect in several respects. First of all, Standar No. 108 does not prohibit the use of more than one side marker lamp, front, rear, or center, provided the additional lamps do not impair the effectiveness of any required lighting equipment. Secondly, such lamps may be mounted at any height on the trailer body 15 inches or more above the road surface. They need not be 'at the top and bottom or top or bottom.' To the extent that California laws prohibit multiple marker lamps or prescribe mounting of marker lamps other than as permitted by Standard No. 108, those laws are preempted by Section 103(d) of the National Traffic and Motor Vehicle Safety Act of 1966.; Yours truly, Richard B. Dyson, Acting Chief Counsel