January 19, 2021







Mr. Stephen T. Powers

Emergency Safety Solutions, Inc. (ESS)

825 Town & Country Lane

Houston, TX 77024


Dear Mr. Powers:


This letter responds to your request for an interpretation of whether your company’s product, the Hazard Enhanced Lighting Package (HELP) system, would be permitted under Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps, reflective devices, and associated equipment.  As explained below, our answer is yes, but only if the product is automatically activated following a crash that disabled the vehicle on which it is installed, or if manual activation of the system is restricted to when the vehicle is not moving and the parking brake is engaged.


By way of background, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment.  Instead, manufacturers are required to self-certify that their products conform to all applicable FMVSS that are in effect on the date of manufacture, before the product can be offered for sale. Manufacturers must also ensure their products are free of safety-related defects.  This letter represents NHTSA’s opinion concerning whether your product would be permitted under FMVSS No. 108.  It is not an approval of your product, nor is it an endorsement of the safety claims made in your initial interpretation request and supplemental submission.


Description of the HELP system


ESS describes the HELP system as an “added functionality” to the vehicle’s turn signal[1] which causes the lamps to flash at an accelerated rate of between 2-6 hertz to create “a strobing effect.”  According to ESS, this function could be activated in two ways: automatically when the vehicle is in “a significant crash,” or manually by pressing the hazard button while the hazard warning system is active and the vehicle is stopped.  In ESS’s supplemental submission, it clarified that, once the HELP system is manually activated, pressing the hazard button would switch the vehicle back to the hazard warning system, and pressing the hazard button again would turn both systems off.  ESS states that if the vehicle starts moving while the HELP system is activated, the system will deactivate, but does not specify whether this deactivation would be in the form of switching to the hazard warning system, or both systems deactivating.  ESS states that the system would use the vehicle’s required turn signal lamps, and that  the lamps would continue to comply with photometric and other requirements when the HELP system is activated.




We view the HELP system as an auxiliary vehicular hazard warning signal flasher that is separate from the required vehicular hazard warning signal flasher, and which is activated under certain limited conditions.  Because it is not required equipment, the primary restriction that FMVSS No. 108 imposes on the HELP system is that the system may not impair the effectiveness of the vehicle’s required lighting equipment.[2] 


As discussed below, we have determined that there are two aspects of the HELP system that could potentially impair the effectiveness of a vehicle’s required lighting equipment. The first relates to the manner in which the driver manually activates the system using the hazard button. The second relates to the actual operation of the HELP system once it is activated.   


System Activation


FMVSS No. 108 requires that a vehicle’s hazard warning system be operated by a switch (or set of switches) that can be actuated with a single action by the driver.[3]  Although this requirement is technically met by the manual switch described in your supplemental submission, since the hazard warning system could be activated with one action both when the HELP system is activated and when it is not activated, we believe that the method of activation you describe would impair the effectiveness of the hazard warning system, as it would confuse a driver who is not familiar with the HELP system.  Since most vehicles are designed in a way that a second press of the hazard button deactivates the hazard warning system, it is reasonable to foresee a scenario in which a driver of a vehicle equipped with the HELP system presses the hazard button intending to turn both systems off, and not realizing that doing so would require two additional presses. 


Given the risk of accidental activation of both the HELP system and the required hazard warning system due to confusion over the activation of the two systems using a single button, we have concluded that incorporating manual activation of the HELP system into the hazard button would impair the effectiveness of lighting equipment required under FMVSS No. 108.


System Operation


In an interpretation letter analyzing impairment under FMVSS No. 108, NHTSA explained that there are, in essence, four ways that a lamp could impair effectiveness: brightness, color, location, and activation pattern.[4]  Since the HELP system operates through the use of the vehicle’s existing required turn signal lamps, and does not purport to alter the brightness, color, or location of those lamps, we do not believe use of the HELP system would impair the effectiveness of the vehicle’s lighting system on the basis of brightness, color, or location. 


However, there are concerns regarding the fourth criterion: the activation pattern of the turn signal lamps.  When a required turn signal lamp is activated using either the required turn signal flasher or the required vehicular hazard warning signal flasher, the vehicle’s turn signal lamps must flash at a rate of 1-2 hertz.[5]­­,[6] ­ ­­­­However, when the turn signal lamps are activated using the HELP system, they would flash at a rate that could be as much as three times higher (2-6 hertz).  Ultimately, the question of whether the HELP system is permitted under FMVSS No. 108 depends on whether this higher flash rate would impair the effectiveness of the vehicle’s required lighting equipment.


We have considered this impairment issue by analyzing the HELP system as it would be used in two separate circumstances.   


First is its capability of automatically activating following a serious crash.  FMVSS No. 108 requires that a hazard warning operating unit be “driver controlled.”  However, as NHTSA explained in letters to Mr. Timothy Bartlett[7] and Mr. Brian Latouf,[8] automatic activation of the hazard warning system is permitted in certain, limited situations in which there was no ambiguity regarding the reason for the hazard system’s activation.  In the Bartlett letter, we stated the hazard warning system could activate automatically following a crash.  In the Latouf letter, we said the hazard warning signals could activate when a vehicle operated using GM’s “Super Cruise” partial automation system comes to a stop after finding the driver unresponsive.  In both situations, the purpose for which the hazard warning system is being used—to warn other road users of the disabled or stopped vehicle—is unambiguous.  


Applying this reasoning to your system, we likewise conclude that the HELP system would not impair a vehicle’s required lighting equipment when limited to automatic activation following a crash that disables the vehicle, such as one in which the air bags are triggered.  As you indicated in your request, the purpose of the HELP system’s 2-6 hertz flash rate is to increase conspicuity of a vehicle in an emergency.  We believe the risk of impairment is low if activated when the vehicle is disabled following a crash, since the crash would almost certainly create an emergency in which conspicuity of the vehicle’s lamps is of primary importance.[9] 


The second circumstance involves the manual activation of the HELP system.  While the HELP system is an auxiliary system that is not subject to the requirements that apply to the hazard warning system, NHTSA has the same concern about the ambiguity of the meaning of the HELP system’s operation that it expressed in the letters to Mr. Bartlett and Mr. Latouf.  Unlike an automatic activation when the vehicle is disabled following a crash, if the system can be manually activated, NHTSA is concerned that the HELP system could be activated in a wide array of non-emergency situations that could confuse other road users.  Given that there is a higher risk of impairment if the vehicle allows manual activation of the HELP system, we have concluded that if it is possible to activate the system manually, your system is permissible under the impairment prohibition only if its activation is restricted to when the vehicle is not moving and either the vehicle is in park or the parking brake is engaged.  Moreover, consistent with our determination in the previous section, the switch that activates the HELP system must be separate from the hazard button, and must be designed so that it is not easily confused with the hazard button.  


Please note that, while this letter finds that the HELP system does not necessarily violate the prohibition on impairment, it is the responsibility of the certifying vehicle manufacturer to ensure that the particular implementation of the system in a vehicle would not impair the effectiveness of required lighting equipment.






                                                                                    Jonathan C. Morrison

                                                                                    Chief Counsel

Dated: 1/19/21

Ref: FMVSS No. 108

[1] You state in your letter that the system would activated the “hazard warning lamps.”  Hazard warning lamps are not a type of lamp that NHTSA regulates.  Rather, vehicles are required to be equipped with a “Vehicular hazard warning signal flasher,” which is a device that, when activated, causes all the vehicle’s turn signal lamps to flash simultaneously.

[2] See FMVSS No. 108, S6.2

[3] See FMVSS No. 108, S9.6.2

[4] https://isearch.nhtsa.gov/files/571.108%20--%20AMA%20--%20Schaye--front%20color%20changing%20light.htm

[5] See FMVSS No. 108, S14., S14., and Figure 2

[6] Although you were correct when you stated in your supplemental submission that this flash rate was chosen in large part due to the limitations of incandescent light sources that existed at the time the standard was adopted, the maximum flash rate is specified in Standard 108, and cannot be changed except through the rulemaking process.

[7] https://isearch.nhtsa.gov/files/23695.ztv.html

[8] https://isearch.nhtsa.gov/files/16-1289%20(GM%20hazard%20innovative)%20--%2028%20Apr%2016%20rsy.htm

[9] To be clear, NHTSA is unable to agree with your assertions that the HELP system would provide the safety benefits you describe in your request and supplemental submission. Our letter today does not endorse or concur with such statements.