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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 13411 - 13420 of 16515
Interpretations Date

ID: nht90-1.52

Open

TYPE: Interpretation-NHTSA

DATE: February 21, 1990

FROM: Dipl.-Ing H. Westermann -- Hella KG Hueck & Co.

TO: Taylor Vinson -- Office of Chief Counsel., NHTSA

TITLE: Request for interpretation - CHMSL unity.

ATTACHMT: Attached to letter dated 4-25-90 To Dipl.-Ing H. Westermann and From Stephen P. Wood; (A35: Std.108); Also attached to letter dated 2-7-90 To Richard van Iderstine and From Dipl.-Ing. H. Westermann

TEXT:

Please receive enclosed our request for interpretation, which had accidentally been addressed to Mr. van Iderstine but we were informed that it is yours responsibility. A major uncertainty has arisen with respect to CHMSL unity, where the CHMSL is mounted on the trunk of a convertible (no rear window, appendix 2 of the letter). By ECE unity is defined but SAE and FMVSS 108 yield no such definition. In absence of a clear definition of unity for CHMSL, please let us know, whether the appropriate ECE definition can be applied and whether the designs as shown in the appendices form a CHMSL unity in the sense of FMVSS 108. A soon answer is very much appreciated.

ID: nht90-1.53

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/22/90

FROM: STEPHEN P. WOOD -- ACTING CHIEF COUNSEL, NHTSA

TO: RICHARD A. KULICS, ESQ.

TITLE: REQUEST FOR RULING IMPORTED VEHICLES - FTZ

ATTACHMT: LETTER DATED 12-5-89 TO TAYLOR VINSON, NHTSA, FROM RICHARD A. KULICS, ATTACHED.

TEXT: This is in reply to your letter of December 5, 1989, to the attention of Taylor Vinson of this Office, on behalf of your clients Liphardt Associates and Pierre Enterprises, Inc.

You have informed us that Liphardt is an Independent Commercial Importer (ICI) under EPA regulations. The vehicles it imports are modified by Pierre. Both entities have the identical mailing address. This location is within a Foreign Trade Zone. You have also informed us that Liphardt/Pierre (L/Pe) will apply for status as a Registered Importer under 49 CFR Part 592. It is the practice of L/PE to transport its nonconforming vehicles directly from the vessel into the Zone, to perform conformance mod ifications in the Zone, and then file a consumption entry, post bond, and submit conformance documentation to DOT. After DOT and EPA have released the vehicle, it is delivered to its owner.

You have requested that L/Pe "be allowed to submit conformity packets to your agency prior to the submission of the consumption entry package, i.e., upon submission of the FTZ entry [transportation of the vehicle into the Zone], so that it may enter the vehicle as 'conforming.'" Under this plan, the current method of operation would remain much the same, except that L/Pe would prepare an HS-7 Declaration Form at the time the vehicle is transported into the Zone. This Form would be submitted to DOT along with a conformity package, for review and release, if appropriate. Then, when the actual consumption entry is filed, the vehicle would be entered as "conforming" merchandise. The purpose of this request "is to eliminate the costs associated with posti ng a special bond purely for DOT purposes", and to speed "up the process of importation, thus reducing the costs associated with storage." As you state, "What L/Pe proposes is that it be allowed to close out the obligation while the vehicle is still in t he custody of the Customs Service."

In substantiation of your request, you have called our attention to certain provisions of 19 CFR Part 146 Foreign Trade Zones, specifically section 146.2 outlining the obligations of Customs' supervision, section 146.10 providing for examination of merch andise necessary to facilitate the proper administration of any law that Customs is authorized to enforce, and section 146.31 stating that admission of merchandise into a Zone is subject to the regulations of the Federal agency concerned.

Under the facts as stated in your letter, we have concluded that your clients must provide a DOT bond under the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1381 et seq.), as amended by the Imported Vehicle Safety Compliance Act of 19 88 (P. L. 100-562), but that there is no legal reason why its obligations to DOT may not be satisfied before the conformed vehicle enters the customs territory of the United States.

As we understand it, the Foreign Trade Zone Act of 1934 (19 U.S.C. 81a et seq.) is intended to establish areas into which merchandise may be imported temporarily, "without being subject to the customs laws of the United States", before being sent "into c ustoms territory of the United States" (section 81c(a)). A Zone therefore is a legal fiction established solely for the administration of customs laws. Section 2(a) of the 1988 Act repealed the authority of the Customs Service over the importation of v ehicles subject to the 1966 Act. Accordingly, the new regulation governing the importation of nonconforming motor vehicles on and after January 31, 1990, 49 CFR Part 591, is not a "customs law" (unlike the existing regulation which is a joint regulation with DOT that specifically applies to importation into the customs territory of the United States (19 CFR 12.80(b)).

In pertinent part, section 108(a)(1)(A) of the 1966 Act (15 U.S.C. 1397(a)(10)(A)) prohibits the importation "into the United States" of nonconforming vehicles. Although a Zone is not generally considered customs territory, in this instance they are bot h within the United States, and an arrangement which defines the "United States" as comprising both customs territory and foreign trade zones has been upheld as valid (Klockner, Inc., v. United States (1984) 8 CIT 3, 590 F. Supp. 1266). Under section 10 8(c) (1) of the 1966 Act, as amended (15 U.S.C. 1397(c)(1)), a nonconforming vehicle "shall be refused entry into the United States" unless "an appropriate bond" has been furnished to ensure that the vehicle will be brought into conformity within a reaso nable time after such importation."

Therefore, because 49 CFR Part 591 is not a "customs law", any distinction between a Zone and customs territory is legally irrelevant for purposes of the 1966 Act. Further, because both a Zone and the customs territory are physically within the boundari es of the United States, an importation of a nonconforming vehicle into either a Zone or the customs territory requires an accompanying DOT conformance bond.

Nevertheless, the 1988 Act does not impose any restrictions upon either DOT or your clients that prohibits them from entering conformed vehicles into customs territory. However, we see the procedure a bit differently than the one you discussed. The HS- 7 Form and its accompanying bond must be completed not later than the admission of the vehicle into the Zone. Customs retains its role of sending these documents to DOT. When conformance work is completed, L/Pe provides certification to DOT. Because o f the current low volume of nonconforming imports, we anticipate that our review will be completed within two weeks of receipt of the certification. If the certification is acceptable, the bond is released, and L/Pe may then enter the vehicle as no long er subject to DOT conformance regulations (or, as you express it, "conforming merchandise"). Thus, L/Pe will be able to close out its obligation while the vehicle remains in the custody of Customs, even though it is not freed from the bond requirement.

As a final comment on the time factor, we intend to require complete documentation only for the initial make, model, and model year (assuming that the initial submission is acceptable). Although L/Pe must keep verification records on each vehicle it con forms, certifications subsequent to an initial submission need not be accompanied by documents, and could be transmitted by FAX. As we see it, these simple certifications would not require extensive review, improving our ability to respond in a more tim ely manner.

ID: nht90-1.54

Open

TYPE: Interpretation-NHTSA

DATE: February 22, 1990

FROM: Keith D. Kroll -- Vice President, Engineering., Hehr International. Inc.

TO: Stephen P. Wood -- Acting Chief Counsel., NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 5-13-90 To Keith D. Kroll and From Stephen P. Wood; (A35; Std.217); Also attached to letter dated 1-26-90 To John G. Sims and From Stephen P. Wood

TEXT:

Hehr International, Inc. manufactures windows and emergency exit windows for buses. We are looking for clarification of the marking of and operating instructions for window emergency exits; specifically, the requirements of paragraphs S5.5.1 and S5.5.2 o f Federal Motor Vehicle Safety Standard (FMVSS) 217, Bus Window Retention and Release.

Per paragraph S5.5.1 of FMVSS 217, "...and each push-out window or other emergency exit shall have the designation "Emergency Exit" followed by concise operating instructions describing each motion necessary to unlatch and open the exit, located within 6 inches of the release mechanism." We interpret this as two labels; one designating the "Emergency Exit" and the other giving unlatching instructions located 6 inches from the latch/es.

With this interpretation, it follows that the legibility requirements of paragraph S5.5.2 apply only to the "Emergency Exit" marking and not to the unlatching instructions. Additionally, S5.5.2 requires the marking must be legible from the aisle with the seats occupied. Again, we interpret this to apply to the "Emergency Exit" marking only. There are many seating configurations where the latch and unlatching instructions (6 " from the latch) are not visible from the aisle because the "adjacent seat" passenger totally covers them.

Our position has, on numerous occasions, been discussed with NHTSA engineers. The most recent was 23 October 1989 with Jeff Jiusippe who further reviewed this with his supervisor, Mr. Robert Kraus, and called back the same day stating that they (NHTSA) a greed with our position.

We receive numerous calls from our various bus window customers on the legibility of the 'unlatching instructions' to which we respond with our position that the 'unlatching instructions' do not have to meet the legibility requirements of paragraph S5.5. 2; S5.5.2 applies to the exit identification only.

We request your written concurrance with the preceeding interpretation of FMVSS paragraphs S5.5.1 and S5.5.2.

ID: nht90-1.55

Open

TYPE: Interpretation-NHTSA

DATE: February 22, 1990

FROM: Dave Baker -- School Bus Inspector

TO: Bev Wilson

TITLE: Re Buses other than School Buses

ATTACHMT: Attached to a copy of a portion of the Minnesota Statutes (text omitted); Also attached to letter dated 3-18-88 from R.C. Rost to Chief Council, NHTSA; Also attached to letter dated 8-26-88 from E.L. Jones to R.C. Rost; Also attached to letter dated 9-7-90 from P.J. Rice to D.L. Giles (A36; Std. 108; VSA 103(d)); Also attached to letter dated 3-14-90 from D.L. Giles to S.P. Wood; Also attached to letter dated 3-8-90 from D.L. Giles to D. Baker; Also attached to memo dated 3-6-90 from B. Wilson to D. Giles

TEXT:

I hope this helps you understand whats going on. You will have to remove those lights you have on your bus. If you have any more questions - contact me at 389-1172 in Mankato. Box 4187, Mankato, MN 56001. Thanks

Attached is a copy of a portion of the Minnesota Statutes (text omitted).

ID: nht90-1.56

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/26/90

FROM: STEPHEN P. WOOD -- ACTING CHIEF COUNSEL, NHTSA

TO: JIM EVANS -- QUALITY CONTROL DEPARTMENT, THE BARGMAN COMPANY

TITLE: NONE

ATTACHMT: LETTER DATED 12-13-89 TO STEPHEN P. WOOD, NHTSA, FROM JIM EVANS, THE BARGMAN CO., ATTACHED; [OCC 4250]

TEXT: This is in reply to your letter of December 13, 1989, with respect to whether the installation of "yellow" reflex reflectors on the rear of motor vehicles is permissible under Standard No. 108. Because the standard uses the term "amber" instead of "yell ow", I shall refer to yellow as amber also.

As you note, the standard requires two red reflex reflectors to be mounted on the rear, but is silent as to whether additional reflectors, amber in color, are permitted. One of your customers has asked you to manufacture an amber turn signal lens that w ould have an amber reflex reflector area around the outer edge. The turn signal lamp would be adjacent to a lamp of apparently identical size and shape with a red lens and reflex reflector area, providing stop and tail lamp functions. The State of Mich igan apparently allows only red reflex reflectors on the rear. You have asked whether reflectors of other colors may be mounted on the rear as long as the required red ones are present, and if it is illegal, whether Standard No. 108 may be amended to el iminate the confusion.

Because an amber reflector is not a required item of lighting equipment that Standard No. 108 specifies to be installed on the rear of a motor vehicle, its acceptability is subject to the general provisions of section S5.1.3. This states, in pertinent p art, that no additional reflective device may be installed that impairs the effectiveness of lighting equipment required by Standard No. 108. It does not appear to us that an amber taillamp lens with an amber reflector would create an impairment. Under Standard No. 108, amber is a permissible color for rear turn signal lamps, and its presence on a reflector surrounding the lamp should not create confusion. Therefore, manufacture, sale, and installation of an amber taillamp lens with an amber reflecto r would not constitute a noncompliance with Standard No. 108.

However, an interpretation by NHTSA that its lighting standard does not forbid the installation of an amber reflex reflector does not mean that a State could not adopt and enforce a law prohibiting such a reflector. Under section 103(d) of the National Traffic and Motor Vehicle Safety Act, a State may impose its own safety requirements covering any aspect of performance that is not covered by Standard No. 108. We construe this provision narrowly, as allowing a State to regulate all lighting equipment that is not specifically required by Standard No. 108. Noting that Section CI 257.691 of the Michigan vehicle lighting code that you enclosed specifies that reflectors "mounted on the rear shall reflect a red color to the rear", the appropriate remedy w ould be to seek an amendment of the Michigan law. This agency presently has no plans to specify yellow as an alternate color for rear reflex reflectors.

ID: nht90-1.57

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/27/90

FROM: STEPHEN P. WOOD -- ACTING CHIEF COUNSEL, NHTSA

TO: GEORGE F. BALL, ESQ. -- LEGAL STAFF, GENERAL MOTORS CORPORATION

TITLE: NONE

ATTACHMT: LETTER DATED 1/23/90 TO STEPHEN P. WOOD, NHTSA, FROM GEORGE F. BALL, GM, ATTACHED; [OCC 4355]

TEXT: This is in response to your letter of January 23, 1990 asking for an interpretation of Standard No. 201, Occupant Protection in Interior Impact (49 CFR 571.201). Specifically, you asked whether the requirements of S3.3 of Standard No. 201, which apply o nly to "interior compartment doors," are applicable to a portion of a new cupholder design now being developed by GM.

At the outset, I would like to note that section 114 of the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1403) makes a vehicle's manufacturer responsible for certifying that the vehicle complies with all applicable provisions of the F ederal motor vehicle safety standards. For this reason, NHTSA has no authority to approve, endorse, or offer assurances of compliance for any vehicle designs or features. NHTSA will, however, tentatively state our opinion of how the safety standards wo uld apply to a vehicle design or feature. It is important that the manufacturer be aware that these tentative statements of agency opinion are based entirely on the information presented to the agency by the manufacturer, and that the agency opinions may change after NHTSA has had an opportunity to examine the vehicle itself or otherwise acquire additional information.

With those caveats, I believe that S3.3 of Standard No. 201 would not apply to your cupholder design, as explained more fully below. In your letter, you stated that General Motors plans to offer a vehicle with a cupholder permanently installed in the co nsole assembly between the driver and right front passenger positions. The cupholder assembly would include a pivot, which would allow the cupholder to recess into the console when it is not needed. When the cupholder is recessed, the bottom face of th e cupholder assembly would be flush with the console

P2

assembly. I concur with your opinion that the bottom face of the cupholder would not appear to be covered by section 3.3 of Standard No. 201, because that bottom face does not appear to be an "interior compartment door" as that term is defined at 49 CFR 571.3.

The term "interior compartment door" is defined at 49 CFR 571.3 as "any door in the interior of the vehicle installed by the manufacturer as a cover for storage space normally used for personal effects." According to your letter, when the bottom of the c upholder is facing the driver and passenger (which you state is the only configuration in which it could be considered a cover), there is no storage space for personal effects.

The agency has made clear that the term "interior compartment door" does not refer to every door that covers a compartment that could potentially be used as a storage space for personal effects. For example, ash trays and spare tire compartment doors in station wagons are capable of being used as a storage space for some personal effects. However, the preamble to the final rule that added S3.3 to Standard No. 201 expressly stated that S3.3 did not apply to the covers for ash trays and spare tire compa rtment doors in the Standard. 33 FR 15794 (October 25, 1968). Additionally, the agency has stated in previous interpretations that S3.3 of Standard No. 201 does not apply to doors in the interior of a vehicle that do not cover a storage space for perso nal effects. Hence, the door to a fuse box in the interior of a vehicle was said not to be subject to S3.3 in a July 3, 1984 letter to Mr. Bruce Henderson, and the outside surface of a fold-down table was said to be not subject to S3.3 in a January 31, 1 986 letter to Mr. Russ Bomhoff.

Applying this reasoning to your new cupholder design, we would tentatively conclude that, when the cupholder is retracted, the bottom face of the cupholder is not an interior compartment door subject to S3.3 of Standard No. 201. I do not believe that th e compartment that would be covered by the bottom face of the cupholder when it is retracted would be a storage space for personal effects. Even if the compartment were capable of being used as a storage space for personal effects, it would not have been installed by the manufacturer for that purpose. Therefore, the bottom face of the cupholder would not be considered an "interior compartment door" within the meaning of the definition of that term in 49 CFR 571.3, and would not be subject to the requir ements of S3.3 of Standard No. 201.

ID: nht90-1.58

Open

TYPE: Interpretation-NHTSA

DATE: February 27, 1990

FROM: Delbert N. Pier -- Legislation and Compliance Coordinator, Hyundai America Technical Center, Inc. TO: Stephen Wood, Esq. -- Acting Chief Counsel, NHTSA

TITLE: FMVSS Number 107, Reflective Surfaces

ATTACHMT: Attached to letter dated 7-16-90 to Delbert N. Pier from Paul Jackson Rice; (A35; Greenbook Std. No. 107) TEXT:

Hyundai requests assistance with an interpretation regarding Federal Motor Vehicle Safety Standard, Number 107 (reflective surfaces).

It is Hyundai's intention to test the surface visible on the windshield wiper blade rail spring. In accordance with ASTM Designation D 523-62T, Hyundai has set up a test specimen for the specular gloss test to accomplish this, see attachment.

Because of the limited amount of area (side "B") allowable for the light source to reflect into the specular reflectance meter, Hyundai is using several rail springs gathered together. As shown in the attachment, this allows for the adequate reflective surface to accomplish the test. Hyundai believes this specimen shows sound engineering judgement and is a satisfactory way to conduct this test.

Hyundai is requesting an interpretation on this specimen as an acceptable means of conducting the test for establishing compliance with FMVSS, Number 107.

Thank you for your assistance in this matter. Should further clarification be needed, do not hesitate to contact me at the telephone number listed above.

ID: nht90-1.59

Open

TYPE: Interpretation-NHTSA

DATE: February 27, 1990

FROM: Don James -- Contracts, Stone Bennett Corporation

TO: Docket Section -- NHTSA

TITLE: Re Docket No. 88-16; Notice 3

ATTACHMT: Attached to diagram of the toggle installation & envelope (graphics omitted); Also attached to diagram of control panel with auto-neutral (graphics omitted); Also attached to diagram of control panels (text and graphics omitted); Also attached to letter dated 10-12-90 from P.J. Rice (Signature by K.W. Weinstein) to D. James (A36; Std. 102); Also attached to copy of 54 FR 29042, 7-11-89 and 55 FR 1226, 1-12-90, regarding 49 CFR Part 571 and FMVSS 201 (text omitted)

TEXT:

The above referenced Docket concerns the FMVSS Standard No. 102 and the proposed changes as they relate to Automatic Transmissions without a Park Position.

Stone Bennett Corporation has been manufacturing transmission shifting mechanisms since 1973. These mechanisms utilize pneumatics, hydraulics, or, electromotive force or any combination of the three to shift the transmission on the demand of the operato r. In all cases the transmission ranges are indicated by a series of light indicators or a sunshine readable digital display that indicates only the range selected. The method of selecting ranges is not the classic floor mounted or column mounted shift levers. Stone Bennett Corporation uses a toggle mechanism or two pushbutton switches to effect the range to range shift operation. That is, to execute a shift to an adjacent range when in the Neutral position, it will be necessary to depress a shift bu tton (push the toggle lever) to move from neutral to reverse or from neutral to drive. It is necessary to depress the pushbutton or push the toggle lever and release to allow movement through the range sequence. An example is to shift three range posit ions from drive to second in a sequence of RND321. The operator must press/release to shift to 3rd and press/release to shift from 3rd to 2nd and simarily to shift the opposite direction.

The overriding purpose of this letter is to ask for a ruling on the acceptability of providing a label indicating the range sequence on the body of the shift control console. Please see the attached documents for a visual understanding of the request.

Your immediate attention to this matter will be greatly appreciated.

ID: nht90-1.6

Open

TYPE: INTERPRETATION-NHTSA

DATE: JANUARY 5, 1990

FROM: HANK KMIECIK -- STEERABLE CARRIAGES

TO: OFFICE CHIEF COUNSEL -- NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 3-13-90 TO HANK KMIECIK; STEERABLE CARRIAGES, FROM STEPHEN P. WOOD, NHTSA; [A35; VSA 108(A)(2)(A); 108(A)(1)(A)]

TEXT: On the advice of Robert Clarke and Michael Trentacoste, I am writing to inform you of our intent to manufacture axle steering systems for tractor trailers, long bodied straight trucks, buses and special application vehicles and ask you to review the syst em and advise us if it is in compliance with the applicable DOT regulations.

Description Axle Steering System

The axle steering system provides a method and means for steering the rear of a tractor trailer combination by turning the wheels of the trailer to increase the maneuverability of the entire unit during turning maneuvers, parking, provide additional mane uverability in congested traffic and under close clearance conditions. This is accomplished by means of a steering apparatus comprising sections of steel beams, hydraulic cylinder/motor assembly, 2- locking pin assemblies, steering pin assembly, manifol d assembly, air reservoir, battery and control panel.

The sections of steel beams used as the framework for the system are welded to one of the existing trailer axles for retrofit to an existing trailer or incorporated simply into the manufacturing process for new trailers. The steering/axle assembly is po sitioned under the trailer chassis and welded to it. The other system components are installed in their designated locations on the trailer chassis (see the enclosed illustrations) and the control panel to operate the steering system is located in the ca b on the dash panel for ease of operation by the driver. No modifications are made or required to the suspension system or the brake system of the axle.

The axle steering system requires approximately 16 man hours to install by a skilled truck mechanic and helper.

The system is not designed for full-time rear wheel steering at highway speeds.

System Operation

Assume the trailer has 2 axles on the rear. Both axles have an air suspension. The ideal setup is air suspension and lift kit on each axle. The axle steering system works with either setup, combination of or the non steering axle can be a spring axle.

For example, when the driver needs to make a right hand turn onto a congested road, the driver would bring the tractor trailer momentarily to a full stop, a short distance before the intersection and engage the axle steering system. Using the control pan el (Illegible Word) in the cab, the driver releases air from, or otherwise deactivates, the rear axle suspension system of the steering axle, effectively raising one set of rear wheels off the ground. The driver then selects the right hand turn button o n the control panel which activates a two way double acting hydraulic cylinder which applies force against the raised rear wheel steering assembly in the direction it is desired to change the orientation of the rear axle. After the steering assembly is turned in the desired direction the two locking pins are engaged into the locking hole positions on the curved beam firmly locking the axle/steering system into the desired position, air is readmitted into the rear air/axle suspension system causing the steering wheels to return firmly to the ground. Air is now released from the air/axle suspension system of the adjacent axle which raises the wheels of the adjacent axle and eliminates the ground friction they would create in making the turn. The drive r of the truck then proceeds at slow speed to make the desired turn or other maneuver with the one axle turned.

After completing such turn, the vehicle is brought to a stop and the driver repeats the above procedure in reverse order, removing the steering wheels from the road surface turning the rear wheel steering assembly to the normal driving position and engag e locking pins before resuming highway travel.

It takes 10-15 seconds from the time the driver stops the truck to complete the initial steering sequence and about the same time to return the axle steering system back to the locked position for normal highway travel after making the turn.

Enclosed is a short video tape showing the axle steering system in action.

If you require further information or a demonstration, please do not hesitate to ask.

AXLE STEERING SYSTEM

Steerable Carriages 1/10/90

(Graphics omitted)

AXLE STEERING SYSTEM

(Graphics omitted)

AXLE STEERING SYSTEM

(Graphics omitted)

ID: nht90-1.60

Open

TYPE: INTERPRETATION-NHTSA

DATE: MARCH 2, 1990

FROM: HENRY J. NOWAK -- MEMBER OF CONGRESS

TO: GENERAL JERRY RALPH CURRY -- ADMINISTRATOR, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 3-16-90 TO BARBARA J. KELLEHER-WALSH, HARTLEY ASSOCS. INC., FROM STEPHEN P. WOOD, NHTSA; [REDBOOK A35; STD. 213]; ALSO ATTACHED LETTER DATED 2-20-90 TO HENRY J. NOWAK FROM BARBARA J. KELLEHER-WALSH, AND LETTER DATED 8-2 2-89 TO DEIRDRE FUJITA, OFFICE OF GENERAL COUNSEL FROM BARBARA J. KELLEHER-WALSH.

TEXT: Enclosed is self-explanatory correspondence from my constituent, Ms. Barbara J. Kelleher-Walsh.

I am requesting that very careful attention and consideration be expedited in providing Ms. Kelleher-Walsh the letter of interpretation, and please provide me a written response.

With best wishes and kindest regards.

ENCS.

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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