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 |
|---|---|
| search results table | |
ID: aiam1673OpenMr. John W. Wooster, Wooster's Automotive, 1185 Palm Avenue, Imperial Beach, CA 92032; Mr. John W. Wooster Wooster's Automotive 1185 Palm Avenue Imperial Beach CA 92032; Dear Mr. Wooster: This is in reply to your letter of August 22, 1974, in which yo describe a particular 5-yard dump truck which you purchased and ask whether the vehicle's weight ratings are consistent with federal requirements. You describe the vehicle as having a gross vehicle weight rating of 15,000 pounds. However, when loaded with 4-5 yards of topsoil, which you state is not an abnormal load for the truck, the vehicle weight exceeds the stated gross vehicle weight rating. The weight of the unloaded vehicle is 8600 pounds.; NHTSA Certification regulations require the vehicle manufacturer t specify on the vehicle's certification label a gross vehicle weight rating, and a gross axle weight rating for each axle. The gross vehicle weight rating must be at least the sum of the unloaded vehicle weight, 150 pounds for each passenger, and the vehicle's rated cargo load (49 CFR S567.5(a)(5)). While the unloaded vehicle weight and passenger weight can be determined objectively, the rated cargo load is a figure set by the manufacturer, based on his own assessment of the vehicle's carrying capacity and the maximum load at which the vehicle may be safely operated. The NHTSA accepts such ratings by manufacturers when established in good faith. the ratings on the certification label are intended to advise purchasers of the load limitations for the vehicle and should be considered at the time of purchase. We cannot say, therefore, on the basis of the facts you present, that the vehicle failed to conform to Federal requirements. Moreover, we cannot agree with your statement that the 'size of the brakes' do not comply with federal standards. No Federal braking standards were applicable to truck manufactured at the time this truck was purchased (July 1973).; Yours truly, Richard B. Dyson, Acting Chief Counsel |
|
ID: aiam4021OpenMr. William E. Sandham, Sales Manager, OEM Division, Velvac, Inc., 2900 South 160th Street, New Berlin, WI 53151; Mr. William E. Sandham Sales Manager OEM Division Velvac Inc. 2900 South 160th Street New Berlin WI 53151; Dear Mr. Sandham: Thank you for your letter of May 21, 1985, concerning the vertica adjustment of rearview mirrors for trucks. You asked us to clarify whether the standard requires a mirror both to tilt, as shown in your sketch 'A,' and to move up and down its mounting bracket, as shown in your sketch 'B.' As discussed below, a truck mirror can meet the adjustment requirement by either tilting or by moving up and down its mounting bracket.; The agency has not specified the means used to provide a vertica adjustment. We would consider a mirror which tilts, as shown in your sketch 'B,' as meeting the adjustment requirement. You should know that the agency has interpreted this vertical adjustment requirement for trucks to mean that adjustment with tools is allowed. The use of tools is justified because trucks and buses are generally driven for longer periods of time by the same driver and thus the mirror does not have to be continually adjusted.; Please note that S6.1(a) of Standard No. 111 also permits trucks with GVWR of 10,000 pounds or less to be equipped with rearview mirrors which meet the performance requirements for passenger cars in section S5, instead of the requirements for trucks in S6.1(b), S7, or S8. If the passenger car specifications are chosen, the driver must be able to adjust the inside and outside rearview mirrors in both vertical and horizontal directions by tilting them. The agency has not permitted the use of tools for adjusting passenger car mirrors, since passenger cars are often driven by different drivers who will need to quickly and easily adjust their mirrors. A mirror mounted on a universal ball socket joint, for example, meets this requirement. In this situation, the vertical tilting adjustment shown in your sketch 'A' would appear to comply as long as that mirror could also be adjusted horizontally by tilting. The vertical sliding adjustment shown in sketch 'B' apparently would not meet this requirement because it appears to require the use of tools to make the adjustment.; A copy of the current version of Standard No. 111 is enclosed. I hop this information is helpful to you.; Sincerely, Erika Z. Jones, Chief Counsel |
|
ID: aiam1223OpenMr. Jerry M. Schneider, 5475 Northwest highway, Chicago, Illinois 60630; Mr. Jerry M. Schneider 5475 Northwest highway Chicago Illinois 60630; Dear Mr. Schneider: This is in response to your letter of August 21, 1973, asking whethe Standard 125 Warning devices are required to be installed as original equipment in motor homes by the manufacturer.; Standard 125 is an equipment standard, not a vehicle standard. Thi means that it is directed at the manufacturer of the devices, not vehicle manufacturers. Therefore the standard doesnot(sic) make installation of the device mandatory in any motor vehicle. The Bureau of Motor Carrier Safety, however, has made the use of the device mandatory by interstate carries subject to its regulation.; For your information, future requests for information should b directed to the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, S.W., Washington, D.C. 20590, and not the Docket Section, which essentially is a repository of comments which do not receive a reply.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam5260OpenMr. Ray Paradis Manufacturing Manager Dakota Mfg. Co., Inc. Box 1188 Mitchell, SD 57301; Mr. Ray Paradis Manufacturing Manager Dakota Mfg. Co. Inc. Box 1188 Mitchell SD 57301; Dear Mr. Paradis: This responds to your FAX of November 18, 1993 requesting a clarification of our letter of November 16 as it applies to the rear of the trailers shown in items; 5 and 7 which accompanied your letter of August 31, 1993. As we advised yo with respect to rear markings, Standard No. 108 requires a horizontal strip of retroreflective sheeting across the full width of the trailer. With respect to the trailer shown in; 7, retroreflective tape can be applied across the full width of th 'approach ramp' to meet the requirements since the ramp will be in the down position when the trailer is moving. As we further advised you, paragraph S5.7.1.3(b) anticipates that the length of the color segments may have to be modified to facilitate using material near rear lamps. In the worst cases of trailers with rear surfaces no wider than the minimum required for lamps, breaks in the rear treatment are unavoidable to clear the lamps. But NHTSA expects the manufacturer to minimize the breaks by using red material adjacent to red lamps. With respect to; 5, we recommend applying red/white conspicuity treatment on either sid of the identification lamps, with red material used in the remaining outboard areas. I hope that this answers your questions. Sincerely John Womack Acting Chief Counsel; |
|
ID: aiam0598OpenMr. John Hall, Dayton Steel Foundry Company, P.O. Box 1022, Dayton, OH 45401; Mr. John Hall Dayton Steel Foundry Company P.O. Box 1022 Dayton OH 45401; Dear Mr. Hall: This is in reply to your letter of February 2, 1972, in which you aske whether the temperature range specified in S6.2.6 of Motor Vehicle Safety Standard No. 121 was an initial temperature range or a range applicable throughout the stop.; In the new issuance of the standard, published in the February 24 1972, issue of the *Federal Register*, the section has been amended to make it clear that the range is the range of initial brake temperature on each stop.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam4888OpenMr. David McCormick First Company 9571 Alden Lenexa, KS 66215; Mr. David McCormick First Company 9571 Alden Lenexa KS 66215; Dear Mr. McCormick: This responds to your letter to Stephen Wood, ou Assistant Chief Counsel for Rulemaking, seeking information about any provisions of Federal law that might apply to a belt positioning device for children. Based on the information provided in your letter, it appears that this device attaches to the seat back of the rear seat and includes an adjustable cushioned head support and an adjustable 'convenience center,' which serves to reroute the belt to offer a better belt fit for a child occupant of the position. For your information, I have enclosed two letters in which we have provided a general description of how Federal requirements might apply to belt positioning devices. The first is a February 11, 1988 letter to Mr. Roderick Boutin and the other is a November 22, 1988 letter to Ms. Claire Haven. These letters explain the applicable Federal requirements and the letter to Mr. Boutin sets forth some safety concerns applicable to that particular design. In addition, I have enclosed an information sheet for new manufacturers of motor vehicles and motor vehicle equipment that explains how to obtain copies of our safety standards and other regulations. I hope this information is helpful. Sincerely, Paul Jackson Rice Chief Counsel; |
|
ID: aiam0062OpenMr. Jack Cedarblade, Northern California Ready Mixed Concrete and Materials Association, 155 Montgomery Street, San Francisco, CA 94104; Mr. Jack Cedarblade Northern California Ready Mixed Concrete and Materials Association 155 Montgomery Street San Francisco CA 94104; Dear Mr. Cedarblade: Thank you for your letter of April 8, 1968, to Mr. George Nield concerning the location requirements for clearance lamps as specified by Federal Motor Vehicle Safety Standard No. 108.; Enclosed is a copy of the Federal Motor Vehicle Safety Standards (wit amendments and interpretations through February 15, 1968). Standard No. 108 appears on page 39 of this publication. The location requirements for clearance lamps are included in Table II (page 50), of the standard. Since the requirements specify locations as near as practicable to the upper left and right extreme edges of the vehicle, the exact locations will vary, depending upon the design and utilization of the vehicle on which the lamps are mounted. When the rear identification lamps are mounted at the extreme height of the vehicle, rear clearance lamps may be mounted at optional heights. I would also point out that Standard No. 108 is applicable to new vehicles manufactured for sale on or after the effective date of the standard.; With respect to the requirements of Standard No. 108, I must point ou that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the standard.; Thank you for writing. Sincerely, David A. Fay, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
|
ID: aiam4922OpenSgt. Danny Wilkinson Texas Department of Public Safety Motor Vehicle Inspection Service 350 West IH-30 Garland, TX 75043; Sgt. Danny Wilkinson Texas Department of Public Safety Motor Vehicle Inspection Service 350 West IH-30 Garland TX 75043; "Dear Sgt. Wilkinson: This responds to your letter of October 17, 1991 informing us that Texas has adopted Federal Motor Vehicle Safety Standard No. 108 for State safety inspections. You report that motorists wish to repair rear lighting devices with patch kits, rather than replacing them with new equipment, and ask whether Standard No. 108 affords a basis for making use of repair kits illegal. You mention in particular the following sections of Standard No. 108: S5.1.3 ('additional equipment,' with attention to impairment of effectiveness), S5.3.1.1 ('location of required and other equipment'), and S5.7 ('replacement equipment.') I am afraid that Standard No. l08 does not contain a completely satisfactory answer to your question, primarily because the standard deals with the performance of new vehicle equipment, and not the maintenance of that performance after the vehicle is in use, which is the thrust of the Texas requirement. Under the regulatory scheme of the National Traffic and Motor Vehicle Safety Act, a motor vehicle is not required to remain in compliance with Standard No. l08 (or any Federal safety standard) after the vehicle is sold to its first purchaser for purposes other than resale. It is possible, of course, that a vehicle could suffer damage to its rear lighting assemblies before its first sale, requiring repair by the dealer. Assuming, for the sake of argument, the not-very likely scenario that the new car dealer selling the car chose to use a patch kit rather than to replace a damaged lens or lamp, the legal question is not whether the patch is additional lighting equipment that could impair the effectiveness of the required lighting equipment (paragraph S5.1.3). The legal question is whether the repaired vehicle meets Standard No. l08: for example, would the repaired lamp meet the photometric requirements with the patch in place, would it meet the environmental tests (moisture, dust, corrosion) that the lamp and vehicle originally met in order to be certified as conforming to Standard No. l08? If the answer to these questions is affirmative, the patch would be acceptable under Federal law, if negative, then the patch would not be acceptable under Standard No. l08. The Safety Act does not directly address repair of damage after a vehicle has been sold. Although paragraph S5.7 of Standard No. l08 requires replacement lighting equipment to meet the same standards as original equipment, neither it nor the Safety Act specify how a vehicle is to be repaired. The Safety Act does prohibit motor vehicle repair businesses (and dealers, distributors, and manufacturers) from creating a noncompliance after a vehicle has been sold, but if that noncompliance is already in existence, such as could occur with a broken lens, there is no statutory obligation to repair the vehicle so that it once again complies with Standard No. 108. Under the Safety Act, a State is preempted from establishing or continuing in effect a motor vehicle safety standard that is not identical to a Federal motor vehicle safety standard covering the same aspect of performance. The purpose of this requirement is to remove the burden on interstate commerce that would be created if the standards to be met by a vehicle or equipment manufacturer varied from State to State. However, the preemption clause does not preclude a State from regulation of modifications to vehicles after sale. Thus, the State of Texas may prohibit the use of patch kits to repair any lighting devices without violating the Safety Act. Furthermore, if Texas laws for the operation of vehicles in use are identical to Standard No. l08, the State could prohibit any original equipment which impairs the effectiveness of the performance of any original equipment lamp or reflective device required by Standard No. l08, or replacement lighting equipment that is not certified to the same requirements as the original lighting equipment. I hope that this information has been helpful to you. Sincerely, Paul Jackson Rice Chief Counsel"; |
|
ID: aiam5630OpenMr. Orlando Ferreira Orion Bus Industries Ltd. 5395 Maingate Drive Mississauga, Ontario L4W 1G6 Canada; Mr. Orlando Ferreira Orion Bus Industries Ltd. 5395 Maingate Drive Mississauga Ontario L4W 1G6 Canada; "Dear Mr. Ferreira: This responds to your FAX message to Mr. Jer Medlin of this agency, asking whether your 'master switch' on a transit bus must be illuminated pursuant to Standard No. 101, Controls and displays. Your master switch has four controls, 'engine stop,' 'run,' 'lights,' and 'park.' In a telephone conversation with Mr. Medlin, you explained that your 'run' control functions as an 'engine start' control, and your 'park' control functions as a 'clearance lamps systems' control. As explained below, Standard No. 101 specifies illumination for the 'engine stop' and 'park' controls, but not for the 'run' and 'light' controls. In addition, there are identification requirements for those controls. Your drawing of the master switch shows that the switch resembles a tuning knob on a radio. Like a knob, the switch can be turned to each of the above four positions, one position at a time. Because turning the master switch knob to each position activates the described function, we would consider each position to be a separate control. You write that the master switch will be placed on a 'driver's side control panel,' a location that subjects controls to Standard No. 101's illumination requirements. S5.3.1 of Standard No. 101 (referencing Tables 1 and 1(a) Identification and Illumination of Controls), specifies that if: a control is provided, is listed in column 1 of either Table 1 or 1(a), and is accompanied by the word 'yes' in the corresponding space in column 4, Illumination, of the table, the 'identification ... of any control' shall be capable of being illuminated whenever the headlights are activated. 'Engine stop' control The identification of the 'engine stop' control must be capable of being illuminated whenever the headlights are activated. This is because in Tables 1 and 1(a), the 'engine stop' control is specified in column 1, and accompanied by 'yes' in the corresponding space in column 4 of each table. 'Park' control Two issues are raised by your 'park' control. The first relates to Standard No. 101's requirements for identifying controls. Under the standard, the control that regulates the parking lights is the 'clearance lamps system' control, rather than the 'park' control. Since your control regulates the parking lights, it must be identified as 'Marker Lamps', 'MK Lps' or (as you propose) with the symbol specified in column 3 of Table 1. Labeling the control as 'park' could confuse some persons into thinking 'park' is a transmission park position. The second issue is the illumination requirement. The identification of the control must be capable of being illuminated whenever the headlights are activated. As noted above, your park control has to be identified as 'Marker Lamps' or 'MK Lps'. In Table 1, the control is specified in column 1, and accompanied by 'yes' in the corresponding space in column 4. Thus, the control must be illuminated. 'Run' control The same two issues discussed in our answer directly above, pertain to this control. First is Standard No. 101's requirements for identifying controls. Under the standard the control that will start the engine must be identified as 'engine start' (rather than 'run') as described in both Tables 1 and 1(a), when it is separate from the key locking system (as is yours). The control need not be illuminated. In both Tables 1 and 1(a), the 'engine start' control (which is the correct identification of the control) is specified in column 1, without a corresponding 'yes' for illumination in column 4 of either table. 'Lights' control The same two issues discussed above are relevant here. The illustration you enclosed with your letter shows that you use both the word 'Lights' and an identifying symbol to identify your Lights control. We are not sure that you are correctly using the symbol. The symbol you use is listed in Table 1 of Standard No. 101 as that for the master lighting switch. A master lighting switch regulates all exterior vehicle lights. If your 'lights' control only regulates headlamps and taillamps, and not all exterior vehicle lights, please designate the headlamps and taillamps as specified in column 3 of Table 1. The 'lights' control need not be illuminated. In both Tables 1 and 1(a), the 'lights' control is specified in column 2, without a corresponding 'yes' for illumination in column 4 of either table. I hope this information is helpful. If you need any further information, please contact Ms. Dorothy Nakama of my staff at (202) 366-2992. Our FAX number is (202) 366-3820. Sincerely, John Womack Acting Chief Counsel"; |
|
ID: aiam0432OpenRoger Levin, Esq., Room 2000, 100 W. Monroe Street, Chicago, IL 60603; Roger Levin Esq. Room 2000 100 W. Monroe Street Chicago IL 60603; Dear Mr. Levin: This is in reply to your letter of July 23, 1971, concerning certai aspects of Motor Vehicle Safety Standard No. 205, 'Glazing Materials.'; You are correct in your statement that Standard No. 205, which has bee in effect since January 1, 1968, and was amended on September 19, 1968 (33 F.R. 14163) and March 1, 1969 (34 F.R. 3688), applies to a manufacturer of automobile sunroofs, 'either in kits for installation by others, or for direct installation by the sunroof manufacturer, in either case after the car has been completed.' To comply with the standard the sunroof material must meet the requirements for either AS1, AS2, AS3, AS4, AS5, AS10, or AS11 glazing material, as specified in ANSI Standard (formerly ASA Standard) Z26.1-1966, July 15, 1966. The 1969 amendment to this standard has not, as you state, been incorporated into Standard No. 205. However, a notice of proposed rulemaking published January 9, 1971 (36 F.R. 326), proposed to include that amendment. This matter is presently under consideration.; You are also correct in stating that a sunroof is an item of moto vehicle equipment, and not a motor vehicle. Certification may be made, pursuant to section 114 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1403), by the statement you submit, 'Material Certified to Comply with U.S. Motor Vehicle Safety Standard No. 205', followed by the name of the manufacturer.; We are pleased to be of assistance. Lawrence R. Schneider, Acting Chief Counsel |
|
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.