Interpretation ID: aiam3125
Executive Engineer
Vehicle Regulations and Standards
Engineering Division
Mack Trucks
Inc.
P.O. Box 1761
Allentown
PA 18105;
Dear Mr. Brown:#I regret the delay in responding to your letter of Jul 19, 1979, which requested an interpretation of Federal Motor Vehicle Safety Standard 101-80, *Controls and Displays*. You asked whether placing the turn signal symbol on the turn signal control shown in your illustration so that the arrows are vertical would comply with the standard.#The answer is no. Section 5.2.1 of the standard requires that the turn signal symbol appear perceptually upright to the driver. The purpose of that requirement is to ensure quick and accurate indentification (sic) of the vehicle controls. The upright position of a symbol is determined by referring to column 3 of Table 1 of Safety Standard 101-80. That table shows that the upright position for the turn signal symbol is with the arrows pointing horizontally. Thus, the arrows must point essentially horizontally in the motor vehicle.#Since the symbols required by Safety Standard 101-80 were selected in order to facilitate international standardization and harmonization, it is important that they not be significantly altered from one vehicle to another. This is particularly important in order to ensure that drivers become familiar with the meaning of various symbols including the turn signal symbol.#However. Safety Standard 101-80 does permit manufacturers to supplement the symbols designated in Table 1 of the standard with additional words or symbols for the purpose of clarity. Therefore, nothing in the standard would prevent your company from adding additional symbols, such as curved thinner arrows next to the turn signal symbol, to indicate mode of operation.#Sincerely, Frank Berndt, Chief Counsel;