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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



Displaying 5771 - 5780 of 16517
Interpretations Date

ID: aiam4085

Open
Confidential; Confidential;

Dear Confidential: This is in response to your letter of June 21, 1985 requesting pursuant to 49 CFR Part 512, confidential treatment for your letter of that date and of the two attachments thereto.; Your request has been granted. NHTSA will treat your June 21, 198 letter and the attachments confidentially. Pursuant to a January 22, 1986 telephone conversation between (Confidential) and Heidi Lewis Coleman of my staff, our letter to you regarding this matter will be made publicly available to the extent indicated on the copy which is enclosed. Also enclosed is a copy of this confidentiality determination, which indicates the extent to which it will be made publicly available.; Sincerely, Kathleen DeMeter, Assistant Chief Counsel for General Law

ID: aiam3740

Open
Mr. Paul Scully, Vice President, Peterson Manufacturing Company, 4200 East 135th Street, Grandview, MO 64030; Mr. Paul Scully
Vice President
Peterson Manufacturing Company
4200 East 135th Street
Grandview
MO 64030;

Dear Mr. Scully: This is in reply to your letter of July 22, 1983, to Mr. Cavey of thi agency.; With respect to paragraph S4.1.1.7 of Standard No. 108 *Lamps Reflective Devices, and Associated Equipment* you have stated your understanding that that paragraph applies only to turn signal lamps manufactured between January 1, 1972 and September 1, 1973, and that turn signal lamps must now comply with SAE Standard J588e, September 1970.; Paragraph S4.1.1.7 did allow vehicular compliance with SAE J588d as a option to J588e. J588d required that any turn signal lamp used on a vehicle whose overall width was 80 inches or more have a minimum of 12 square inches effective projected luminous lens area. On the other hand, SAE J588e requires a minimum of 8 square inches effective projected luminous lens area on all single compartment rear turn signal lamps, regardless of vehicle width. However, on vehicles 80 inches or more in overall width, two turn signal lamps or compartments per side may be mounted closer together than 22 inches provided each meets single compartment photometric requirements and each has a minimum effective projected luminous lens area of 12 square inches. Thus, your understanding is correct.; I would also point out that, pursuant to Section S4.7.1 of Standard No 108, the continued manufacture of turn signal lamps meeting J588d is permissible as replacement equipment for vehicles manufactured between January 1, 1972 and September 1, 1978.; Mr. Cavey has provided the copy of BMCS regulations which is enclosed. Sincerely, Frank Berndt, Chief Counsel

ID: aiam2852

Open
Lawrence F. Henneberger, Esq., Robert W. Green, Esq., Messrs. Arent, Fox, Kintner, Plotkin & Kahn, 1815 H Street, N.W., Washington, DC 20006; Lawrence F. Henneberger
Esq.
Robert W. Green
Esq.
Messrs. Arent
Fox
Kintner
Plotkin & Kahn
1815 H Street
N.W.
Washington
DC 20006;

Dear Messrs. Henneberger and Green: This is in reply to your letter of June 9, 1978, on behalf of you client, Jacobs Manufacturing Company ('Jacobs' herein).; Jacobs manufactures a diesel engine retarder system which 'produce significant deceleration of a large truck so equipped.' Jacobs believes that some means should be provided to warn following vehicles when a retarder is in use. It proposes to connect the retarder activation switch to the hazard warning system when a retarder is installed either as original equipment or as an aftermarket accessory. You have asked whether installation of the system would violate either 49 CFR 571.108, Motor Vehicle Safety Standard No. 108, or 15 U.S.C. 1397(a) (2) (A), section 108(a) (2) (A) of the National Traffic and Motor Vehicle Safety Act.; Paragraph S4.1.3 of Motor Vehicle Safety Standard No. 108 prohibits th installation of any device as original equipment that would impair the effectiveness of lighting equipment required by the standard. Paragraph S4.1.1 and Table I require trucks whose overall width is 80 inches or greater to be equipped with a hazard warning flasher system. The Jacobs device may not be installed if it would impair the effectiveness of the required hazard warning flasher system. The intended use of the Jacobs device is that it act as a warning of a decelerating vehicle in the roadway which may present a potential hazard. As such it augments the hazard warning system and, in our view, would tend to enhance rather than impair its effectiveness. Therefore, it may be installed as original equipment without violating S4.1.3. We have no provisions that would either permit or preclude its sale as an aftermarket device, and whether it is permissible as such is a matter to be determined by the laws of the States in which the truck is registered and operated, as well as those administered by the Bureau of Motor Carrier Safety, Federal Highway Administration.; Section 108(a) (2) (A) of the Act prohibits a manufacturer, amon others, from rendering inoperative, in whole or in part, any device installed in accordance with a Federal motor vehicle safety standard. Nothing in your letter indicates that the Jacobs device will affect the hazard warning signal flasher's ability to function at times when the Jacobs device is in operation, and therefore, it does not appear that its installation violates section 108(a) (2) (A).; Sincerely, Joseph J. Levin, Jr., Chief Counsel

ID: aiam1287

Open
Mr. Erik Sundelin, Trelleborgs Gummifabriks Aktiebolag Fack, S-231 01 TRELLEBORG/Sweden; Mr. Erik Sundelin
Trelleborgs Gummifabriks Aktiebolag Fack
S-231 01 TRELLEBORG/Sweden;

Dear Mr. Sundelin: #This is in reply to your letter of August 22, 1973 responding to our reply of June 26, 1973, to your letter of May 28, 1973. We informed you in the June 26 letter that labeling a passenger car tire, 'Max Load 1200 Lbs. At 36 psi,' would not be consistent with Motor Vehicle Safety Standard No. 109 because this label does not make it clear that 36 psi is the maximum permissible inflation pressure. In your letter of August 22 you state that you have already manufactured tires labeled in this manner, and ask whether such tires may be imported into the United States in their present form. #The answer to this question is no. As we have determined that this labeling does not conform to Standard No. 109, the tires in question cannot be imported into the United States unless the labeling is modified to conform the standard. #Sincerely, Richard B. Dyson, Assistant Chief Counsel;

ID: aiam3594

Open
File, Interpretation--S 571.7(f); File
Interpretation--S 571.7(f);

Telephone Interpretation On August 4, 1982, Mike Segraves of Trailmobile presented th hypothetical to me of whether a remanufactured trailer could be purchased by the remanufacturer before modification and leased to its former owner after modification without it being considered newly manufactured for purpose of compliance with the Federal motor vehicle safety standards.; He found a contradiction between 49 CFR S571.7(f) and the preambl establishing it. Subsection (f)(2) imposes the restriction that the remanufactured trailer is 'an existing trailer' which 'is owned or leased by the user of the reassembled vehicle.' Yet the preamble (41 FR 27073, July 1, 1976) states that the restriction 'would require that the owner or lessor of the existing trailer also be the owner or lessor of the rebuilt trailer'. I found no interpretation letters on the point.; Subsection (f)(2) was adopted verbatim from the proposal (40 FR 58154 December 15, 1975). It appears to have originated from a petition by Monon Trailer Company suggesting, in the words of the preamble 'that the rebuilt trailer be sold only to the owner of the trailer from which it was rebuilt'. NHTSA agreed, believing that 'the requirement that the trailer be sold to the original owner under its original identity would be included to prevent large-scale evasion of the standard by parties who might attempt to recycle old, unreliable equipment that would normally be junked'.; Upon close examination, I see no conflict. I believe that 571.7(f)(2 and the preamble language mean simply that in order for the trailer to qualify for the exclusion, it must be either owned by or leased by the same person both before and after manufacture. A 'lessor' is an 'owner' but a 'lessor' cannot be the 'user', thus, the word 'leased' refers to a lessee rather than a lessor. The preamble clarifies that the 'owner or lessor' of the existing trailer must be the owner or lessor of the rebuilt trailer. But 'owner' as 'vendor' is outside the exclusion, and sale of the trailer *after* remanufacture is prohibited. But sale *before* remanufacture is not precluded. Trailmobile as 'owner', independent of its status as remanufacturer, remains the 'owner' after its property is reconstructed, and as 'lessor' may enter into a lease with the former owner or any other party without bringing the trailer under the umbrella of the new vehicle standards.; After consulting with Roger Tilton I so advised Mr. Segraves. Z. Taylor Vinson, Senior Staff Attorney

ID: aiam4251

Open
Mr. G.T. Doe General Manager - Product Design Lotus Engineering, Ltd. Norwich, Norfolk NR14 8EZ England GREAT BRITAIN; Mr. G.T. Doe General Manager - Product Design Lotus Engineering
Ltd. Norwich
Norfolk NR14 8EZ England GREAT BRITAIN;

"Dear Mr. Doe: This responds to your letter in which you asked how th conversion of a convertible to a hardtop would affect the applicability of two of our safety standards. I regret the delay in this response. You explained that Lotus proposes to introduce a new two seat convertible into the United States. These cars will be imported into the United States and delivered to dealers and distributors as convertibles. However, you stated that Lotus intends to offer a 'factory manufactured and approved' hardtop conversion for these convertibles. Dealers would remove the convertible canopy and support frame and permanently attach a hard roof to the vehicle. The converted cars would be sold to the public as hardtops. You then asked whether the convertible cars would be treated as hardtops or convertibles for the purposes of Standards No. 208 and No. 216. I would like to set the foundation for answering your specific questions by first addressing a few basic points. The agency has defined a convertible as 'a vehicle whose A-pillar (or windshield peripheral support) is not joined at the top with the B-pillar or other rear roof support rearward of the B-pillar by a fixed rigid structural member.' In this case, your kit will join the A-pillar and B-pillar of the convertible by a fixed rigid structural member. After this conversion, the car would no longer be a convertible, as that term is used by NHTSA. Section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safety Act of 1966, as amended (15 U.S.C. 1397(a)(1)(A)) provides that, 'No person shall manufacture for sale, sell, offer for sale, or introduce or deliver for introduction in interstate commerce, or import into the United States, any motor vehicle ... manufactured on or after the date any Federal motor vehicle safety standard takes effect under this title unless it is in conformity with such standard except as provided in subsection (b) of this section.' This provision makes clear that a dealer would be prohibited from selling a hardtop passenger car that did not comply with all safety standards applicable to hardtops, even though the passenger car conformed to all standards applicable to convertibles when it was imported and delivered to the dealer. The exceptions set forth in section 108(b) of the Safety Act would not permit a dealer to sell a car that had been converted from a complying convertible into a hardtop without being modified to comply with all safety standard requirements applicable to hardtops. Section 108(b)(1) specifies that the prohibition on selling or offering to sell passenger cars that do not conform with all safety standards does not apply after the first purchase of the car in good faith for purposes other than resale. However, a dealer that converts a car into a different type before the first purchase could not rely on this exception. Section 108(b)(2) specifies that the prohibition on selling nonconforming cars shall not apply to any person who establishes that he or she did not have reason to know in the exercise of due care that the car did not conform to the safety standards, or to a person who holds a certification of conformity from the manufacturer or importer of the car, unless that person knows that the car does not conform. In the case of this proposed conversion, the dealers would hold a certificate of conformity from Lotus or the importer for the convertible version of this car. However, the dealers would also know that they had converted the car into a hardtop, and that they had no certificate of conformity for the car as a hardtop. Further, such dealers would have reason to know that the requirements in the safety standards for hardtops are different from those for convertibles. Finally, the dealers would know that the hardtop version of the car had not been certified as conforming to all applicable standard requirements. Indeed, as alterers of completed vehicles, the dealers would be required to recertify the cars under 49 CFR /567.7. The exceptions to section 108(a)(1)(A)'s prohibition set forth in sections 108(b)(3)-(5) are not applicable in this situation. Hence, dealers could not legally sell these converted cars to the public for the first time, unless the cars conform with all safety standards applicable to hardtop passenger cars. With this background, I will now address your specific questions. They were: 1. Convertibles are not required to conform to the roof crush requirements of Standard No. 216, Roof Crush Resistance - Passenger Cars (49 CFR /571.216). Would the designation of the vehicle as a convertible remain unaffected by the hardtop conversion? ANSWER: As explained above, the answer to this question is no. Any car that is converted to a hardtop before its first sale for purposes other than resale must comply with all standards applicable to hardtops. Assuming such cars do not conform to the rollover test requirements in section S5.3 of Standard No. 208 by means that require no action by vehicle occupants, these cars would be subject to the requirements of Standard No. 216. 2. Would the requirement for seating and restraint system provision remain unaffected by the hardtop conversion? ANSWER: No. It is not clear to which seating requirements you are referring. However, you stated in your letter, 'It is conceivable that, although the shelf would not be recognised as a seating area, small occupants could travel in this area.' The requirements for seating systems are dependent upon the existence of a 'designated seating position.' This term is defined in 49 CFR /571.3 as follows: 'Designated seating position' means any plan view location capable of accommodating a person at least as large as a 5th percentile adult female, if the overall seat configuration and design and vehicle design is such that the position is likely to be used as a seating position while the vehicle is in motion, except for auxiliary seating accommodations such as temporary or folding jump seats. We cannot determine from your letter if the shelf area is capable of accommodating a 5th percentile adult female, nor can we determine whether the area's configuration and design is such that the position is likely to be used as a seating position while the vehicle is in motion. It appears from the enclosed drawings that any person riding in the shelf area would have to sit on the floor or prop themselves on the wheel wells. If this is true, the shelf area would not be considered to have any designated seating positions. The required occupant restraint system would also be affected by converting the convertibles into hardtops. As explained above, cars that are converted to hardtops by dealers before sale to the public would not be treated as convertibles for the purposes of Standard No. 208, Occupant Crash Protection (49 CFR /571.208). Since the cars would no longer be considered convertibles, they would have to be equipped with lap/shoulder belts at both designated seating positions, pursuant to section S4.1.2.3.1 of Standard No. 208. Additionally, these cars would not be eligible for the exemption for convertibles during the phase-in of the automatic restraint requirements in Standard No. 208. I sent a letter to General Motors (GM) on September 18, 1987, stating that GM may be considered the manufacturer of Lotus cars that are imported into the United States (copy enclosed). Therefore, any Lotus cars that are converted into hardtops would have to be included in GM's annual production to determine compliance with the phase-in requirement, pursuant to sections S4.1.3.1.2, S4.1.3.2.2, and S4.1.3.3.2 of Standard No. 208. I have also sent a copy of this letter to General Motors. Sincerely, Erika Z. Jones Chief Counsel Enclosure cc: J. Douglas Hand, Esq. Legal Staff, General Motors Corporation P.O. Box 33122 Detroit, MI 48232 /";

ID: aiam1053

Open
Mr. J. L. Foster, Office Manager, The Procter and Gamble Distributing Company, Post Office Box 60114, New Orleans, LA 70160; Mr. J. L. Foster
Office Manager
The Procter and Gamble Distributing Company
Post Office Box 60114
New Orleans
LA 70160;

Dear Mr. Foster: This is in response to your request for odometer disclosure form applicable to the State of Florida. The letter appears to be a blanket request for forms from all the states in which you do business.; The Motor Vehicle Information and Cost Savings Act and the accompanyin regulations were purposely made flexible and simple to permit the states and affected transferors maximum latitude in conforming to the Act. In fact, the States have no duties under the Act. Many of the States that you have contacted will probably indicate that no changes will be made to their laws and regulations. Some states may change their Title forms or their disclosure forms to accomodate (sic) the federal statement.; It is the transferor's responsibility to make the required disclosur and again maximum latitude is permitted. No federally-printed form is required nor is one available. A transferor may write his own form, make use of a state form which conveys the same information, or use one of the commercially printed forms now available. So far as the federal requirements are concerned you may use an identical form in all the states. An example of an acceptable format is enclosed for your information.; Yours truly, Richard B. Dyson, Assistant Chief Counsel

ID: aiam4601

Open
The Honorable Harry Reid United States Senate Washington, D.C. 20510; The Honorable Harry Reid United States Senate Washington
D.C. 20510;

"Dear Senator Reid: Thank you for your letter to the Department o Transportation, on behalf of the City of Sparks, Nevada. That city's police department has received six new patrol cars equipped with air bags. According to the City Attorney for Sparks, the city police cars are often required to push disabled vehicles out of travel lanes of highways and the police officers are afraid that the air bags will be activated during these pushing operations. You asked if the Department of Transportation would authorize the Sparks police department to disconnect the air bags on its patrol cars. I am pleased to have this opportunity to explain our law and regulations to you. The National Traffic and Motor Vehicle Safety Act (the Safety Act) authorizes this agency to issue safety standards applicable to new vehicles and new items of motor vehicle equipment. We have exercised this authority to issue Standard No. 208, Occupant Crash Protection (49 CFR /571.208). Standard No. 208 requires all 1990 model year cars to be equipped with automatic crash protection, and specified percentages of each manufacturer's 1987, 1988, and 1989 model year cars to be so equipped. Chrysler, the manufacturer of the patrol cars in question, has chosen to comply with the requirement for automatic crash protection by installing air bags in these police cars. When a safety standard like Standard No. 208 is in effect and applicable to new passenger cars, the Safety Act prohibits any person from manufacturing, selling or offering for sale, importing, or introducing in interstate commerce any new car that does not comply with the safety standard. However, the Safety Act provides that these prohibitions do not apply after the first purchase of the car 'in good faith for purposes other than resale.' Hence, the Federal requirement that the cars comply with all applicable safety standards ceased to apply when the Sparks city police department purchased these cars, since the police department bought these cars in good faith to use them as police patrol cars, not to resell them. After the first purchase of a car in good faith for purposes other than resale, the Safety Act prohibits any manufacturer, distributor, dealer, or repair business from 'rendering inoperative' any device or element of design installed in the car in compliance with an applicable safety standard. Obviously, disconnecting air bag systems would have that effect. Accordingly, Federal law prohibits any manufacturer, distributor, dealer, or repair shop from disconnecting the air bag systems on the Sparks police department cars. Please note that the Safety Act does not prohibit individual vehicle owners from rendering inoperative safety features on their own vehicles. Hence, the City of Sparks does not need any sort of 'authorization' from this agency to disconnect the air bag systems on the city's police cars. The City of Sparks is permitted to disconnect the air bags on its own vehicles without violating any Federal law, just as any resident of Sparks can remove any safety equipment they like from their own vehicles without violating Federal law. Such removals may, however, violate the laws of the State of Nevada. I recommend that the city carefully consider the effects of disconnecting the air bag systems in its police cars, even though Federal law does not prohibit the city from doing so. The air bags in those cars are an effective means of protecting vehicle occupants in frontal crashes. As to the possibility of inadvertent deployment of air bags in police cars, I note that the agency has entered into a contract under which police cars have been retrofitted with air bag systems, without a single reported instance of an air bag detonation while pushing a disabled vehicle. Enclosed is a report with some additional information on this contract. Particularly since the City of Sparks police officers face the possibility of becoming involved in high speed pursuit situations, we believe those police officers deserve the benefits of automatic crash protection in their police cars. I hope this information is helpful. Please do not hesitate to contact us if you have any further questions or need additional information on this subject. Sincerely, Stephen P. Wood Acting Chief Counsel Enclosure";

ID: aiam1403

Open
Mr. Robert W. Borgert, Spartan Design Inc., 24151 Telegraph Road, Southfield, MI 48075; Mr. Robert W. Borgert
Spartan Design Inc.
24151 Telegraph Road
Southfield
MI 48075;

Dear Mr. Borgert: This is in reply to your letter of January 21, 1974, asking for ou comments on your defect notification letter.; In describing the defect (your third paragraph) as required by Sectio 577.4(c), you should state specifically that the placement of the lamps fails to conform to Federal Motor Vehicle Safety Standard No. 108, and indicate, in general terms, what is the appropriate location. In addition, section 577.4(c) requires the inclusion of precautions the purchaser can take. We believe one precaution that should be included where a lighting problem is concerned is to recommend that night driving be limited as much as possible.; When we have received a corrected copy, we will close our files in thi matter.; Sincerely, Lawrence R. Schneider, Chief Counsel

ID: aiam5440

Open
Mr. C.N. Littler Motor Coach Industries Administrator Regulatory Affairs 1558 Wilson Place Winnipeg, Manitoba R3T 0Y4 CANADA; Mr. C.N. Littler Motor Coach Industries Administrator Regulatory Affairs 1558 Wilson Place Winnipeg
Manitoba R3T 0Y4 CANADA;

"Dear Mr. Littler: This responds to your letter concerning whether New York State law addressing the in-use stopping ability of privately owned motor coaches is preempted by Federal law. I apologize for the delay in our response. The New York law states that a vehicle must be capable of stopping 'at a rate of deceleration equivalent to a stop within 22.2 feet from a speed of 20 miles per hour.' You believe that 103(d) of the National Traffic and Motor Vehicle Safety Act ('Safety Act') preempts the New York law, since the state law is not identical to Federal motor vehicle safety standard No. 121, Air Brake Systems. Please note that the Safety Act has been codified at 49 U.S.C. 30101 et seq. and that the citation for 103(d) is now 49 U.S.C. 30103. As explained below, Standard No. 121 currently does not have stopping distance requirements in effect, therefore, the New York law is not currently preempted by a Federal safety standard. Nevertheless, the agency has issued a proposal to reinstate stopping distance requirements in Standard No. 121. (58 FR 11003, February 23, 1993). If the agency issues a final rule to reinstate stopping distances, then any more stringent requirements in the New York law (addressing the same aspects of performance as Standard No. 121) would be preempted. Title 49 U.S.C. 30103 states: Whenever a Federal motor vehicle safety standard ... is in effect, no State or political subdivision of a State shall have any authority either to establish, or to continue in effect, with respect to any motor vehicle or item of motor vehicle equipment any safety standard applicable to the same aspect of performance of such vehicle or item of equipment which is not identical to the Federal standard. That provision preempts New York's law if there is a Federal safety standard in effect, the state law covers the same aspect of performance as that Federal standard, and the State law is not identical to the Federal safety standard. While you are correct that Standard No. 121 refers to stopping performance in S5.3.1, you apparently were not aware of a provision in S3 that states Notwithstanding any language to the contrary, sections S5.3.1, S5.3.1.1, S5.3.2, S5.3.2.1, S5.3.2.2, S5.7.1, S5.7.3(a) and S5.7.3(b) of this standard are not applicable to trucks and trailers, and section S5.3.1 of this standard is not applicable to buses. The agency amended the standard to include this provision as the result of a ruling in PACCAR v. NHTSA, 573 F.2d 632, (9th Cir. 1978), cert. denied, 439 U.S. 862 (1978), in which a Federal Court of Appeals invalidated Standard No. 121's stopping distance requirements until the agency obtains 'more probative and convincing data evidencing the reliability and safety of vehicles that are equipped with antilock.' While the provision did not originally cover buses other than school buses, NHTSA extended the provision to non-school buses in 1987. See 52 FR 20602. Because there are no Federal stopping distance requirements in effect, the New York law is not preempted. As noted above, NHTSA has issued a notice proposing to reinstate stopping distance requirements for air braked vehicles. The agency is currently reviewing comments to that proposal, and may issue a final rule reinstating stopping distance requirements. If the agency decides to amend Standard No. 121 to include such requirements, then any more stringent requirements in the New York law (addressing the same aspects of performance as Standard No. 121) would be preempted. I note that the New York law applies to vehicles in use, while Standard No. 121 applies to new vehicles. In general, State laws governing the operation of vehicles are not preempted by inconsistent Federal motor vehicle safety standards unless the State law is more stringent than the Federal standard (with respect to the same aspect of performance). A more stringent law would be preempted, since it would preclude the sale of vehicles that comply with Federal standards. I also note that the in-use braking performance of many motor coaches is regulated by the Federal Highway Administration. We have referred your letter to that agency's Office of Motor Carrier Standards concerning the issue of whether its regulations preempt the New York law. I hope this information is helpful. If you have any questions about NHTSA's safety standards, please feel free to contact Marvin Shaw at this address or by telephone at (202) 366-2992. If you wish to contact someone in the Federal Highway Administration's Office of Chief Counsel concerning the motor carrier standards, please call Charles Medalen at (202) 366-1354. Sincerely, John Womack Acting Chief Counsel Enclosure ";

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.

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