NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
| Interpretations | Date |
|---|---|
ID: nht94-1.43OpenTYPE: Interpretation-NHTSA DATE: February 7, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Donald W. Vierimaa -- Vice President - Engineering, Truck Trailer Manufacturing Association TITLE: None ATTACHMT: Attached to letter dated 9/2/93 from Donald W. Vierimaa to John Womack (OCC-9050) TEXT: We have reviewed your letter of September 2, 1993, asking for three interpretations of S5.7 of Federal Motor Vehicle Safety Standard No. 108, the provisions that relate to heavy trailer conspicuity. You have set forth the metric dimensions specified in S5.7, together with corresponding values under the headings "English (actual)," and "English (nominal)." The latter is a rounding off of the values of "English (actual)." Your first question is whet her you may consider the English (nominal) dimensions equivalent for the purpose of compliance with Standard No. 108. We assume that you would like to provide measurements in the conventional manner to your members who may not be familiar with the metric system, as a means of assisting them to comply with the conspicuity requirements that become effective December 1, 19 93. However, the Federal motor vehicle safety standards are not expressed in equivalents, but in precise values, whether metric or conventional, and there can be no rounded "equivalences" for purposes of compliance with Standard No. 108. SAE J1322 JUN8 5 "Preferred Conversion Values for Dimensions in Lighting" which you reference has not been incorporated into Standard No. 108. In implementation of Departmental and national policy, NHTSA has begun to specify the requirements of the Federal motor vehic le safety standards using metric system values, and manufacturers are expected to learn and to comply with them. We would also like to correct a misimpression indicated in your letter. You have placed a single asterisk by certain metric values reflecting your assumption that these are minimum values. This is incorrect; the standard expresses these values as fixed values rather than minimum ones. However, you are correct in your identification as minimum of those values that are not designated by an asterisk. Your second question concerns the location of rear and side sheeting. You point out that cargo tank trailers may have a "vertical surface" only at their "belt line" which may be as high as 2.3 m above the ground. You ask whether retroreflective sheetin g may be located higher that 1.25 m if there is no vertical surface lower than this height "without installing structure just for the sheeting." As adopted, Standard No. 108 specified a mounting height as close as practicable to 1.25 m. However, in a n otice published on October 6, 1993, NHTSA amended the requirement to "as close as practicable to not less than 375 mm and not more than 1525 mm above the road surface." The practicability qualification allows manufacturers to choose a location for consp icuity treatment that is outside the specified range to avoid body modifications that might otherwise be required to mount the material within the specified range. The manufacturers of conspicuity material certify its performance as mounted on a vehicle in a vertical plane. Trailer manufacturers are expected to mount the material in a vertical plane or as close to a vertical plane as the trailer shape offers. In the case of your hypothetical tank trailer without a suitable vertical surface below the belt line of the tank, reflective material at the belt line, whether 2.3 m or higher, would be considered to have been mounted as close as practicable to the upper s pecification of the height range (1.525 m). As NHTSA observed when it adopted the original mounting height specification with its practicability provision, flexibility in the vertical location of conspicuity material is necessary for compliance of some tank trailers. However, it should not be overlooked that other types of tank trailers may have vertical surfaces on the frames, fenders, or other equipment well suited for conspicuity material. Your third question presents five Figures and asks with respect to each whether the vertical and horizontal sheeting for the upper right and left contours, as specified by S5.7.1.4.1(b), may be of the dimensions and locations shown. This section require s application of two pairs of white strips of sheeting, each pair consisting of strips 300 mm long, applied "vertically" and "horizontally" to the contours "as close to the top of the trailer and as far apart as practicable." With respect to Figures 1 a nd 2 (van trailers), we shall assume that the horizontal strips are mounted as close to the top of the trailer as practicable. Figure 1 depicts two separate strips at right angles to each other, each 300 mm in length. This design is not in accordance w ith Standard No. 108. The side strip does not appear mounted as close to the top of the trailer as practicable, and the top strips do not appear to be mounted as far apart as practicable. While the presence of door hinges may necessitate designs simila r to Figure 1, this design, as drawn on an unobstructed surface, does not comply. To effect compliance, either the side strips should be moved upwards, or the top strips should be moved closer to the outside corners. Figure 2 depicts two strips joined at the corners to make an inverted "L." Each leg of the "L" is 300 mm in length when measured from the outside, top to bottom, or side to side. This configuration is in accordance with S5.7.1.4.1(b). Figures 3 and 4 present alternative conspicuity treatments for liquid tank trailers where the body is curved rather than rectangular. In Figure 3, two strips 30 mm in length intersect at an angle greater than 90 degrees. In Figure 4, a curved strip 600 mm in length follows the contour of the body. Paragraph S5.7.1.4.1(b) of Standard No. 108 requires marking the upper outer contours of the body with strips "applied horizontally and vertically to the right and left upper contours of the body ...." Howe ver, the rear contours of a tank body are rounded rather than vertical and horizontal. In view of this fact, the agency accepts the treatment shown in your Figure 3 as meeting the requirement for horizontal and vertical application. The design of Figur e 4 does not differ in any significant way, and we consider that it is equivalent. Finally, Figure 5 depicts a dry bulk trailer with a 300 mm strip centered horizontally at the top of a round body, and two strips of the same length placed lower, at an angle slightly off of vertical, but far from the edges of the body contour. We under stand that the body of the trailer tapers to a blunt end represented by the circle upon which the horizontal conspicuity treatment is laced. As the approximately vertical strips cannot be placed on the tapering trailer body, they should be located as fa r apart as practicable, and the depicted location appears to represent that placement. Similarly, if two horizontal strips cannot be placed on the trailer body, NHTSA will not question the compliance of the vehicle based on the provision of a single, cen ter strip of retroreflective material. |
|
ID: nht88-2.13OpenTYPE: INTERPRETATION-NHTSA DATE: 05/02/88 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: Durham & Associates, P.C. TITLE: FMVSS INTERPRETATION TEXT: Robert R. Keatinge, Esq. Durham & Associates, P.C. Suite 1750 950 17th Street Denver, CO 80202 Dear Mr. Keatinge: This is a response to your letter of December 1, 1987, making this agency to clarify your understanding of 49 CFR S571.7(e). That section reads in part as follows: Combining new and used components. When a new cab is used in the assembly of a truck, the truck will be considered newly manufactured ...unless the engine, transmission, and drive axle(s) (as a minimum) of the assembled vehicle are not new, and at least two of these components were taken from the same vehicle. You referred to my August 11, 1987 letter to Mr. Ernest Parmer, and expressed concern that my having discussed only one aspect of S571.7(e) in that letter has led to some confusion. My letter to Mr. Parmer states that 'a modified school bus or truck is n ot considered a 'new' vehicle if, at a minimum, the engine, transmission, and drive axle(s) are not new and at least two of these three listed components are taken from the same used vehicle.' You stated that while my statement is 'correct,' my response did not address the first clause of this provision: 'When a new cab is used In the assembly of a truck...' you asserted that, a bus should not be considered 'new' unless a new body is attached to the chassis.' Your assertion is correct with respect to S5 71.7(e), but there is another regulation that specifies a vehicle is 'new' if an old body is combined with a new chassis.
By its own terms, S571.7(e) applies only in situations where a new body is combined with either (1) mixed new and used chassis components, or (2) used components from different vehicles. You were correct, then, in asserting that 5571.7(e) applied only to situations involving a new body. For the purposes of the Parmer letter, it Has understood between Mr. Parmer and a member of my staff that the bus bodies in question were new, so that letter did not purport to address the question of combining an old bu s body with new and or/used chassis Components. Many of our prior interpretations have stated that a person who adds a new or used body to a new chassis to produce a school bus is considered the manufacturer of a new school bus, and must certify that the new bus conforms with all applicable safety sta ndards, just as every other school bus manufacturer must. In this case, the new chassis is an incomplete vehicle. 'Incomplete vehicle' is defined in 19 CFR 5568.3 as: an assemblies consisting, as a minimum, of a frame and chassis structure, power train, steering system, suspension system, and braking system, to the extent that those systems are to be part of the completed vehicle, that requires further manufacturing o perations, other than the addition of readily attachable components, such as mirrors or tire and rim assemblies, or minor finishing operations such as painting, to become a completed vehicle. When a new bus chassis is used to produce a vehicle, the person who adds a body - even an old body - is a final-stage manufacturer, within the meaning of 49 CFR 5568.3. Final-Stage manufacturers are required to certify that the completed vehicle conforms with all applicable Federal Motor Vehicle Safety Standards in effect on the date of manufacture. The date of manufacture for these buses cannot be earlier than the date on which the chassis manufacturer completed its work on the chassis and cannot be la ter than the date the final-stage manufacturer completed its manufacturing operations. See 49 CFR S567.5, Requirements for Manufacturers of Vehicles Manufactured in Two or More Stages. Note that neither S571.7(e) nor Part 568 would require a person to certify that a school bus complies with all applicable safety standards, if that person merely rebuilds or replaces an engine, drive axle, or transmission in a bus, or if that person plac es a used bus body on a used chassis. I hope you find this information helpful. Sincerely, Erika Z. Jones Chief Counsel December 4, 1987 Erika Z. Jones, Esq. Chief Counsel National Highway Traffic Safety Administration United States Department of Transportation 700 Seventh Street Washington, D.C. 20890
Re: Your letter of August 11, 1987 to Ernest Farmer Dear Ms. Jones: This letter is to confirm my understanding of 49 CFR S571.7(e) as interpreted by the National Highway Traffic Safety Administration ('NHTSA'). In your letter of August 11, 1987 to Mr. Ernest Farmer, the Director of Pupil Transportation for the Tennessee Department of Education, you twice (at the top of page 2 and in the first paragraph of section 3 on page 3) make reference to the portion of 5571.7(e) which says that a bus will not be considered 'new' if the engine, transmission and drive train are not new and at least two of these components are from the same vehicle. While this statement is a correct statement of part of the test under 5571.7(e) it does not address the part of the regulation which states that a truck (or, here, a bus) will be considered new only if the cab (or, here, a body? is replaced. The descrip tion of the regulation contained in your letter may have been in response to an Inquiry which assumed the replacement of the bus body (as did FR Docket No. 85-22646). On Friday, December 4, 1987 I discussed this point with Joan Tilghman of your office. She confirmed what appears to be the clear reading of S571.7(e) to the effect that the replacement of the engine, transmission and/or rear axle only becomes an issue 'W hen a new cab (here, body) is used in the assembly of a truck (here, bus)...". In other words, a bus should not be considered 'new' unless a new body is attached to the chassis. Unfortunately, there has been some confusion as a result of the letter indicates that the NHTSA is changing the regulation to provide in effect that whenever a new or rebuilt engine, transmission or rear axle is put in a bus the bus must be brought into conformity with current standards regardless of whether the body has been replaced. As discussed above, and as confirmed by Ms. Tilghman, I don't think that was your intention. If the foregoing accurately describes the NHTSA's position, I would appreciate your confirming this to me so that we can correct the misunderstanding. Until this ambiguity is resolved, my client is in a difficult position inasmuch as the governmental age ncies are unsure how to proceed. Your prompt response would therefore be greatly appreciated. If there are any questions in this regard or If I am incorrect in my understanding, I would appreciate your contacting me as soon as possible. Thank you for your consideration in this regard. Sincerely,
Robert R. Keatinge |
|
ID: Copy of 06-007875--6 May 09 rewrite--rsyOpenJeff Ronning, PE Senior Consultant Rocky Mountain Institute 1739 Snowmass Creek Road Snowmass, CO 81654-9199 Dear Mr. Ronning: This responds to your inquiry to the National Highway Traffic Safety Administration (NHTSA) of November 27, 2006. I apologize for the delay in responding. In your letter, you asked for our interpretation of 49 CFR Part 538 as it would apply to a plug-in electric hybrid design for a postal delivery vehicle. You ask for confirmation that your basic vehicle design will qualify as a dual-fuel vehicle so that the United States Postal Service (USPS) can be assured [you] are on the right course. You explained that if the vehicle is fully charged, it would be able to operate completely on electricity for most carriers where the average carrier route is only 15 miles, and that the gasoline engine would be used only for rare long-range travel and peripherals such as heating and all-wheel drive function. On January 9, 2007, you further asked by email whether a flex-fuel engine (i.e., one able to use either petroleum-based gasoline or ethanol E85 fuel) instead of a plain gas engine for the same hybrid vehicle would qualify as a dual-fuel vehicle under Part 538. Based on the information that you provided, either design would qualify as a dual-fuel vehicle for purposes of the dual-fuel CAFE incentive. 49 CFR Part 538, Manufacturing Incentives for Alternative Fuel Vehicles, is likely not directly relevant to the vehicle you described. Part 538 has three basic purposes. First, it establishes minimum driving range criteria to aid in identifying passenger automobiles that qualify as dual-fueled automobiles. Second, it establishes gallon-equivalent measurements for gaseous fuels other than natural gas. And finally, it extends the dual-fuel incentive program through model year 2008. The minimum driving range criteria contained in 538.5 and 538.6 apply only to passenger automobiles. In the context of the CAFE program, passenger automobiles are defined as any automobile (other than an automobile capable of off-highway operation) manufactured primarily for use in the transportation of not more than 10 individuals.[1] Although NHTSA leaves it to automobile manufacturers to classify their vehicles in the first instance for CAFE purposes, we would likely consider a postal delivery vehicle to be a non-passenger automobile (commonly referred to as a light truck), since it is manufactured primarily for carrying cargo, and not for transporting passengers. Thus, the minimum driving range criteria of Part 538 would likely not apply to your vehicle.[2] The other two aspects of Part 538, gallon-equivalent measurements for gaseous fuels other than natural gas, and the extension of the incentive program through MY 2008, also would not apply to your vehicle. Since you described your vehicle as a plug-in hybrid, gallon-equivalent measurements for gaseous fuels would be irrelevant. Further, Part 538s extension of the incentive program has been superseded by the Energy Independence and Security Act (EISA) of 2007, which extended the program by statute through model year 2018.[3] Thus, Part 538 would likely not apply to your vehicle. However, your vehicle may still qualify for the dual-fuel incentive under 49 U.S.C. 32905(b), whether or not 49 CFR Part 538 applies to it. A dual fueled automobile is defined (in relevant part) in 49 U.S.C. 32901(a)(8) as an automobile that: (A) is capable of operating on alternative fuel and on gasoline or diesel fuel; [and] (B) provides equal or superior energy efficiency, as calculated for the applicable model year during fuel economy testing for the United States Government, when operating on alternative fuel as when operating on gasoline or diesel fuel. Alternative fuel, in turn, is defined at 49 U.S.C. 32901(a)(1) as including: (J) electricity (including electricity from solar energy); and (K) any other fuel the Secretary of Transportation prescribes by regulation that is not substantially petroleum and that would yield substantial energy security and environmental benefits. Based on this statutory language, NHTSA interprets electricity as an alternative fuel only if it is not substantially petroleum. The electricity on which the alternative fuel vehicle operates must come from some source other than petroleum-based gasoline pumped into the vehicle; for example, from the grid, as in a plug-in hybrid, or from solar energy as the statute mentions.[4] Thus, we would likely consider a plug-in hybrid like your proposed design, whether it contained a gasoline engine or an engine that could also run on E85, to be a dual fueled automobile under 49 U.S.C. 32901(a)(8). If you have any further questions, please feel free to contact Rebecca Yoon of my staff at (202) 366-2992. Sincerely yours, Stephen P. Wood Acting Chief Counsel ref:538 d.7/24/09 [1] 49 CFR 523.4, see also 49 U.S.C. 32901(a)(18). [2] Nevertheless, we note that it is possible that, in the course of examining your vehicle, NHTSA could conclude that in actuality it would be appropriately classified as a passenger automobile. In that situation, in order to qualify for the dual fuel incentive, your vehicle would be required to conform with Part 538 and 49 U.S.C. 32901(c), which specify that the vehicle must drive a nominal distance of 7.5 miles on its stored capacity of electricity when operated on the EPA urban test cycle and 10.2 miles when operated on the EPA highway test cycle. [3] Pub. L. 110-140, Sec. 109 (Dec. 19, 2007). [4] In contrast, in a regular hybrid electric vehicle, any electricity used to run the vehicle comes from stored regenerative braking force, which is derived from the operation of the gasoline engine. |
2009 |
ID: 12-001952 Matheny capacity includes driver (Standard No. 217)OpenMr. Larry W. Fowler Matheny Motors 3rd & Ann Streets P.O. Box 1304 Parkersburg, WV 26102-1304 Dear Mr. Fowler: This responds to your letter to the National Highway Traffic Safety Administration (NHTSA) asking about Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus Emergency Exits and Window Retention and Release. We apologize for the delay in responding; we regret that we did not receive the January 19, 2012 letter you had sent. You ask for clarification of the term seating capacity as used in Table 1 and Table 2 of FMVSS No. 217, i.e., whether the driver is considered part of the seating capacity of a bus for purposes of determining the additional emergency exits needed under S5.2.3 of the standard. As explained below, our answer is yes, the driver seat is included as part of the seating capacity. In 1992, FMVSS No. 217 was amended to revise the minimum requirements for school bus emergency exits.[1] Instead of requiring all school buses to have the same number of exits, the standard was amended to establish minimum emergency exit space based on the seating capacity of each bus. The amendment determined the number of additional exits using a calculation that was based on the designated seating positions in the bus. Under our regulations, we consider a drivers seat to be a designated seating position.[2] In a 1995 amendment, NHTSA replaced the calculations with simple tables, including Tables 1 and 2.[3] The agency explained that the number of exits required by the tables would be derived from the existing requirement. There was no discussion of changing seating capacity to exclude the drivers seat. Thus, we interpret Tables 1 and 2 as simply reflecting the assumptions and calculations that were used previous to the tables. That being the case, seating capacity includes the drivers seat. It makes sense for seating capacity to include the drivers seat for purposes of Table 1 and 2. In an emergency, the driver will be among the occupants needing to exit the vehicle quickly. Including the drivers position in the calculation supports the goal of having sufficient exits to accommodate the occupants of the bus. I hope this information is helpful. If you have any further questions, please do not hesitate to contact Ms. Deirdre Fujita of my staff at (202) 366-2992. Sincerely, O. Kevin Vincent Chief Counsel Dated: 8/14/12 Ref: Standard No. 217 |
2012 |
ID: 18890.jegOpenMr. Meyer Snyder Dear Mr. Snyder: This responds to your letter asking whether you can have the force of the air bags on your 1995 Toyota Camry "turned down." You asked whether this can be done at your Toyota dealer and, if not, where it could be done, and whether you would have to pay for this modification. As discussed below, there is no legal impediment to vehicle manufacturers and dealers modifying older vehicles so that they have the same kinds of redesigned air bags being offered on most new vehicles. However, such modifications would likely be very complicated and potentially expensive, and we are not aware of any vehicle manufacturers or dealers which make such modifications. You may wish to ask Toyota about whether it is possible to modify your vehicle in this manner and at what cost. By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards that apply to the manufacture and sale of new motor vehicles and new motor vehicle equipment. One of the standards we have issued is Standard No. 208, Occupant Crash Protection (49 CFR 571.208). Manufacturers install air bags in passenger cars as part of complying with the occupant protection requirements of Standard No. 208. While the Federal motor vehicle safety standards apply only to new motor vehicles and new motor vehicle equipment, Federal law limits the modifications that can be made by certain businesses to used vehicles. Manufacturers, distributors, dealers, and repair businesses are prohibited from "knowingly making inoperative" any device or element of a design installed on or in a motor vehicle in compliance with an applicable safety standard (49 U.S.C. 30122). A manufacturer, dealer or other business which modified the air bags on your 1995 Toyota Camry would not violate the "make inoperative" provision if, after the modification, the vehicle continued to meet the relevant requirements in effect either on the date of manufacture or as later amended. In 1997 NHTSA amended Standard No. 208 to make it easier for manufacturers to quickly redesign their air bags, e.g., by reducing the power as compared to previous years. Compliance with the amended requirements would thus not violate the "make inoperative" provision. As noted earlier, however, the modifications that would need to be made to an existing vehicle so that it would have redesigned air bags would likely be very complicated and potentially expensive, and we are not aware of any vehicle manufacturers or dealers which make such modifications. I am pleased to hear that you do not want your air bags turned off. The vast majority of persons, including short persons, are much safer with air bags. Among other things, an air bag will minimize the risk of violently striking the steering wheel and dashboard in a moderate to severe crash. I would also like to point out that there are a few basic steps that you can take to minimize air bag risks, including wearing your safety belts and, when driving, keeping at least 10 inches between the center of the air bag cover and your breastbone. I have enclosed an information brochure, written in the context of making an informed decision about on-off switches, which provides additional information concerning how you can reduce air bag risks. Sincerely, |
1999 |
ID: nht76-2.16OpenDATE: 07/30/76 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Thomas Built Buses, Inc. TITLE: FMVSS INTERPRETATION TEXT: This responds to Thomas Built Buses' June 4, 1976, question whether the requirements in S5.1.3 and S5.1.4 of Standard No. 222, School Bus Seating and Crash Protection, to "Apply additional force . . . through the . . . loading bar until (a specified number) of inch-pounds of energy has been absorbed in deflecting the seat back . . ." can be satisfied in part by the energy that is returned to the load bar as it is withdrawn from the seat back. You also ask if there are minimum or maximum time limits on withdrawal of the loading bar from the seat surface. The requirement for the absorption of a minimum amount of energy in (Illegible Word) the seat back in the forward and rearward directions is calculated to provide adequate measurement of the energy involved in the impact between the bus occupants and the seating in a percentage of school bus crashes. The agency calculated the amount of energy to be consumed by the seat back that would result in adequate protection. The specification requires the seat to "absorb" (i.e., receive without recoil) a specific amount of energy. This value is represented by the amount of energy that is not returned to the loading bar as it is withdrawn. Described graphically, the area that represents returned energy under the seat back force/deflection curve must be subtracted from the entire area that lies under the curve in order to calculate the energy "absorbed" by the seat back. With regard to your second question, no time limits have been established for withdrawal of the loading bar. The agency intends to utilize a withdrawal time that is not more than five minutes so that creep will not be a significant factor in determining energy absorption. Because the time is not specified, the manufacturer is free to use any reasonable time that does not significantly affect the elastic and plastic components of the seat back loading. thomas BUILT BUSES, INC. June 4, 1976 Mr. Bob Krause Office of Standards Enforcement Motor Vehicle Programs U.S. Dept. of Transportation National Highway Traffic Administration Re: Part 571 - Federal Motor Vehicle Safety Standards - Para. 571.222 S5.1.4.1 & S5.1.4.2 Our engineering department is in the process of developing testing and analysis techniques for demonstration of compliance with the referenced section of FMVSS. To ensure that these techniques will meet all requirements, we are in need of further clarification of the paragraphs pertaining to seat back load application. Accordingly, we would appreciate answers from your department on the following specific questions: (1) Para. 571.222 S5.1.4.2 specifies energy absorption of the seat back deflection during load application. What is the significance of or treatment required of the energy returned during the backing off of the loading bar? (2) Are there any requirements regarding elapsed time interval for the load back-off? (3) Same questions re Para. 571.222 S5.1.3 thru S5.1.3.4 - Seat Performance Forward. Thank you for your prompt assistance in answering these questions. Malcolm B. Mathieson Engineering Manager |
|
ID: nht90-3.78OpenTYPE: Interpretation-NHTSA DATE: August 31, 1990 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA; Signature by Stephen P. Wood TO: Samuel Kimmelman -- Engineering Product Manager, Ideal Division, EPICOR Industries, Inc. TITLE: None ATTACHMT: Attached to letter dated 8-2-90 from S. Kimmelman to P.J. Rice (OCC 5074) TEXT: This is in reply to your letter of August 2, 1990, with respect to Motor Vehicle Safety Standard No. 108. It is your understanding that, when a vehicle is delivered to its purchaser with dealer-installed trailer hitch and associated wiring, it must conform to all applicable Federal motor vehicle safety standards. You interpret the standards as requiring thre e specific aspects of performance, and you ask whether we agree with those interpretations. These aspects are: "1. The turn signal flasher must be certified as meeting the FMVSS-108 requirements of a variable load turn signal flasher, over a minimum load equal to that of the vehicle turn signal load and a maximum load equal to that of the vehicle plus the trailer ." This is essentially correct. However, it is not the flasher that is certified but the vehicle in which the flasher is installed; Standard No. 108 does not require certification of original equipment lighting items, only replacement equipment items. Sta ndard No. 108's requirements for turn signal flashers are those of SAE Standard J590b, Automotive Turn Signal Flasher, October 1965, which are incorporated by reference. Under the Standard's Scope, the flashers "are intended to operate at the design loa d for the turn signal system as stated by the manufacturer." If a vehicle is designed for towing purposes, and its manufacturer offers an optional trailer hitch and associated wiring, then that manufacturer must equip the vehicle with a flasher capable of meeting a minimum load equal that of the vehicle turn signal load, and a maximum load equal to that of the vehicle plus the trailer. That will be a variable load turn signal flasher. The manufacturer of the vehicle is the person responsible for ensu ring that the flasher meets the vehicle's design load requirements, and that the vehicle is certified as conforming to Standard No. 108. "2. The hazard warning signal flasher must be certified as meeting the requirements of FMVSS-108 over a load range of 2 lamps to the combined hazard warning loads of the vehicle plus the trailer." This is also essentially correct, and our comments are similar. Standard No. 108's requirements for hazard warning signal flashers are those of SAE Recommended Practice J945 Vehicular Hazard Warning Signal Flasher, February 1966, which are incorporated by reference. The Practice's Scope specifies that the flashers "are required to operate from two signal lamps to the maximum design load. . . . as stated by the manufacturer. Thus, in order for the vehicle manufacturer to certify compliance with Standard No. 108, it must equip the vehicle with a flasher that operates over a load range of two lamps to the total hazard warning system load of the vehicle plus the trailer. "3. The requirement to provide turn signal outage is voided due to the trailer towing capability of the vehicle." This is correct. Under section S5.5.6 of Standard No. 108, any vehicle equipped to tow trailers and which uses a variable-load turn signal flasher is exempted from the failure indication requirements of the SAE standards on turn signals. I hope that this answers your questions. |
|
ID: 1985-04.29OpenTYPE: INTERPRETATION-NHTSA DATE: 11/18/85 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: Mr. David Gruenzner TITLE: FMVSS INTERPRETATION TEXT:
November 18, 1985 Mr. David Gruenzner President, Future Tech Inc. P.O. Box 26B Mankato, MN 56002 Dear Mr. Gruenzner: This is in reply to your letter of September 23, 1985, asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108 as it applies to an aftermarket high-mounted stop lamp/turn signal lamp system. You intend to market three models, as more completely described in the next paragraph. All models are mounted in the interior of the car. Our primary concern is the possibility that the interior-mounted unit will cause undesirable reflections in the rear window, reducing the ability of the operator to judge conditions to the rear of his vehicle as seen through the rear view mirror. For this reason, Standard No. 108 requires the new center-mounted stop lamps mounted on the interior to be provided with means to minimize such reflections. These lamps now in production incorporate shrouds that abut the rear window glazing. Though your after market device would not be prohibited by Standard No. 108 since it does not appear to impair the effectiveness of lighting equipment required by the standard, we encourage you to incorporate design features which will prevent undesirable reflections. Also care should be taken to ensure that, when the device is installed, it does not impair the field of view required for rear view mirrors by Safety Standard No. 111. Your device consists of eight miniature lamps, four mounted on each side of the vertical centerline. We also have some additional concerns about the operation of one of your three models. In the first model, in the turn signal mode, the lamps operate sequentially from the center outward in the direction of the intended turn. In the stop lamp mode, the entire unit will illuminate, "sending a sequential (sic) flashing beam from the middle to both sides." We view the sequential flashing of the lights from the center outwards in the stop lamp mode as prohibited by paragraph S4.6 of the standard which requires all lamps that are flashed for signaling purposes. However, the stop function in the second model is indicated by a steady-burning in use, except for turn signal/hazard warning signal lamps, and headlamps and side marker lamps that are flashed for signaling purposes. However, the stop function in the second model is indicated by a steady-burning light, thus complying with our requirements. In the third model, there will be an additional amber colored lens mounted on top of the red lens. The brake signal will be indicated by a steady red light, while the turn signals will be indicated by flashing amber ones. This method of operation is also acceptable under Standard No. 108 which permits rear turn signals to be either amber or red. We are unable to assist you with State laws that may affect your devices. We suggest you contact the vehicle administrators in the States where you intend to market your system. I hope that this is responsive to your request. Sincerely, Original Signed By Erika Z. Jones Chief Counsel |
|
ID: GF009138OpenMr. Kenneth M. Bush Dear Mr. Bush: This responds to your letter concerning Federal Motor Vehicle Safety Standard (FMVSS) No. 201, "Occupant protection in interior impact". Specifically, you ask whether side curtain air bag tethers are considered a part of the "stowed system" that is subject to reduced impact speed upper interior component performance requirements. As discussed below, the answer is yes. By way of background, S6.2 of FMVSS No. 201 sets minimum performance requirements for upper interior components by establishing target areas that must be properly padded or otherwise have energy absorbing properties to minimize head injury in the event of a crash. Compliance with the upper interior component requirements is determined, in part, by measuring the forces experienced by the Free Motion Headform test device (FMH) when it is propelled into certain targets on the vehicle interior at the speed of 24km/h (15 mph), or in some cases, at the reduced impact speed of 19 km/h (12 mph). Air bag systems are frequently stowed (in their un-deployed state) in the same interior areas where certain test targets are located. Targets located on or near air bag systems are subject to reduced impact speed test requirements because the agency is concerned that requiring areas over the stowed portion of an air bag (or its attachment and other hardware) to meet more stringent 15 mph impact requirement could hinder their development and use. Thus, in order to accommodate the current systems and the development of new or additional air bag systems, we determined that use of a 12 mph impact speed, in conjunction with a full-vehicle dynamic side impact pole test, would best help realize the safety benefits of air bags. In relevant part, S6.2(b)(2) of FMVSS No. 201 reads as follows:
You ask if stowed side curtain tethers are considered part of the "stowed system" under S6.2(b)(2).As used in S6.2(b)(2), "stowed system" refers to a stowed dynamically deployed upper interior head protection system. The language ofS6.2(b)(2) specifies that in determining the area subject to reduced impact speed test requirements, consideration is taken of the stowed system, including mounting and inflation components but exclusive of any cover or covers. Side curtain air bag tethers are a part of the stowed dynamically deployed upper interior head protection system, and they are not "covers". Therefore, they are considered in determining whether the target issubject to reduced impact speed test requirements. If you have any further questions, please feel free to contact George Feygin of my staff at (202) 366-2992. Sincerely, Stephen P. Wood ref:201 |
2006 |
ID: 9719Open Mr. Thomas D. Turner Dear Mr. Turner: This responds to your letter of February 21, 1994, requesting further clarification of the requirements of S5.5.3(c) of Standard No. 217, Bus Emergency Exits and Window Retention and Release (as amended at 57 FR 49413; November 2, 1992). Section S5.5.3(c) states that "(e)ach opening for a required emergency exit shall be outlined around its outside perimeter with a minimum 3 centimeters wide retroreflective tape."The July 7, 1993 letter also stated that the agency planned to issue a correction notice of the November 2, 1992 rule that would specify a minimum size of 2.5 cm for the tape. This notice has not yet been published. Until the correction is issued, NHTSA will not take enforcement measures regarding tape size against a manufacturer who uses 1 inch wide retroreflective tape. Your letter referenced our July 7, 1993 letter to you in which we stated that S5.5.3(c) permits interruptions in the tape necessary to accommodate curved surfaces and functional components. You requested confirmation "that retro-reflective tape around the perimeter of the rear of a school bus can be used to satisfy the requirements of S5.5.3(c)." I cannot interpret the requirements of S5.5.3(c) as you request, since for many, if not most, designs the nearest possible location will be closer than the perimeter of the bus. While we appreciate your concerns about durability if numerous cuts or notches are made to accommodate rivets, our July 7 letter stated that manufacturers have the option of placing the retroreflective tape immediately adjacent to the rivets, rather than over the rivets. As an example, from the illustrations you enclosed, it appears that it may be possible to apply retroreflective tape outside the rivets adjacent to the lower portions of the door. Thus, that would be the nearest possible location, rather than the perimeter of the bus itself. I note, however, that the illustrations do not provide sufficient detail of all obstructions for us to determine the nearest possible location for each design. I also note that your letter stated in support of your request that all school buses are required to have a rear emergency exit. While this is true, the type of emergency exit will vary and retroreflective tape at the perimeter of the exit would allow rescuers to immediately know the precise location of the exit. Moreover, retroreflective tape at the perimeter would enable rescuers to immediately know which type of exit is in this location. This information could be vitally important. Because push-out windows are not required to have a means of releasing the exit from outside the bus (S5.3.3.2), this information would allow rescuers to quickly determine that they should move to the sides of the bus to locate an exit they can open. Your letter asked the agency to treat it as a petition for rulemaking if we did not interpret the standard as you requested. You will be notified of our decision to grant or deny your petition. I hope you find this information helpful. If you have any other questions, please contact us at this address or by phone at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel ref:217 d:3/28/94 |
1994 |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.