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12-000762 W.Thompson III 9 Std. No. 108







William H. Thompson III

146 N. 58 St.,

Philadelphia, PA 19139


Dear Mr. Thompson:


            This responds to your letter dated September 21, 2011.  In that letter, you made inquiries regarding two subjects.  First, you requested that NHTSA revisit its position in its previous letter to you (dated July 29, 2011).[1]  That letter responded to your original request for an interpretation of Federal motor vehicle safety standard (FMVSS) No. 108, Lamps, Reflective Devices, and Associated Equipment.  In that letter, we explained our opinion that your invention, which alters the sequence in which school bus signal lamps will flash, would not comply with FMVSS No. 108.  Second, you state that you are requesting the phase out of the four lamp system and the addition of the equivalent of the yellow traffic light function (as described in [your original request for interpretation]).  We will address each of these requests in the following paragraphs.


(1)   The July 29, 2011 Interpretation Letter

            In our July 2011 interpretation letter, we explained that because your invention would alter the standard lighting scheme of school bus signal lamps, it would impair the effectiveness of the required lamps.  As we have explained on many occasions, traffic safety is enhanced by the familiarity of drivers with standardized lighting signals. 

            In your letter requesting reconsideration of our interpretation, you made arguments specifically in regards to whether or not there is a standard message for the red school bus lamps.  You noted that FMVSS No. 108 permits either an eight-lamp signal system (four red and four amber signal lamps) or a four-lamp signal system (four red signal lamps).  You stated that, given the way that some states utilize the four-lamp signal system (e.g. the red lamps being activated prior to the stop location), there does not seem to be a standard message from the red warning lamps.  You also asserted that your invention does not impair the effectiveness of the required lamps because the two original messages [of the required lamps] are now expanded to three distinct and complementary statements.   

            While we have reviewed your arguments, they do not provide a basis for us to change our interpretation.  The option for school buses to have either an eight-lamp or four-lamp signal system goes back to the 1960s.  While motorists may, in light of this option,

potentially encounter two types of school bus signal systems, school bus signal lamps are standardized to that extent and we believe that motorists are familiar with the messages imparted by these systems. 

Further, while the manner in which school bus owners utilize their vehicle lamps is a matter of state law, the message that the red lamps are intended to convey is clear and is specified in our regulations.  The red lamps on school buses are required to conform with Society of Automotive Engineers (SAE) Standard J887, July 1964 (incorporated by reference as part of FMVSS No. 108, S5.1.4(b)) which states that [s]chool bus red signal lamps are . . . intended to identify a vehicle as school bus and to inform other users of highway that such vehicle is stopped on highway to take on or discharge school children (emphasis added).  

According to your letter, your invention would alter the sequence in which school bus signal lamps flash (by including a stage of lighting where red and amber lights flash concurrently) for the purpose of providing a new kind of signal.  It continues to be our opinion that this would, at the very least, impair the effectiveness of the red signal lamps by changing the standardized meaning of those lamps to mean something other than the meaning specified in SAE Standard J887.

(2)   Requested Changes to FMVSS No. 108


In your letter, you also recommended various changes to FMVSS No. 108s requirements for school bus signal lamps.


  If you wish to petition for rulemaking to amend FMVSS No. 108, you should submit a petition for rulemaking pursuant to the requirements specified in 49 CFR Part 552.  However, you should also be aware of the agencys Statement of Policy regarding petitions for rulemaking on signal lamps.[2]  I am enclosing a copy of that document.  Before submitting a petition to the agency, we recommend that you carefully review that Statement of Policy and make sure that you are submitting the kind of data necessary for us to evaluate your petition.   


We thank you for your interest in improving safety for school children riding in school buses and the surrounding road users. If you have any further questions, please contact Jesse Chang (202-366-2992) of this office.






O. Kevin Vincent

Chief Counsel




Ref: 108


[1] The agencys original response dated July 29, 2011 is available at S5-1-4 William H Thompson III 108 School Bus Lighting Interp Letter.htm.

[2] This Statement of Policy was published in the Federal Register on November 4, 1998. See 63 FR 59482, available at