Welcome to NHTSA's interpretations files.

NHTSA's Chief Counsel interprets the statutes that the agency administers and the regulations that it promulgates. The Chief Counsel's interpretations, issued in the form of letters responding to questions from the motor vehicle industry and the public, represent the definitive view of the agency on the questions addressed and may be relied upon by the regulated industry and members of the public. These interpretations have always been available to the public in the agency's technical reference library in Washington. The World Wide Web enables us to make them available through the Internet.

The Interpretations Database Files

As of November 1996, two new database files are being added to supplement the database of 1988 and later interpretations that have been on the web site since May 1996. Since the Chief Counsel's interpretations file does not contain any letters issued prior to 1988, the General Motors Corporation (GM) and the Association of International Automobile Manufacturers (AIAM) have generously agreed to make their database files, which include pre-1988 interpretations, available to the public at NHTSA's web site. None of the databases contains a complete set of interpretations, but together they contain virtually all interpretations issued since the agency was created. All of the interpretations databases are word searchable, using the "Verity" search engine provided.

Chief Counsel's Database

The Chief Counsel's interpretations file consists of all interpretations issued since January 1988, the date on which the office first began using computer diskettes to store its interpretations. The files will be updated every two weeks. If you are interested in reviewing only the most recent interpretations, you may select either the special "search new interpretations" feature or the special "browse new interpretations" feature. These features will enable you to search the latest interpretations only. Interpretations are filed under the name and address of the person requesting the interpretation.

Once you have completed your search of the Chief Counsel's database, you may then wish to search the GM or AIAM databases for earlier interpretations.

GM and AIAM Databases

Although the GM and AIAM interpretations files contain the majority of interpretation letters issued between 1967 and March 1996, neither database is complete. In particular, nearly all of the interpretation letters that exclusively refer to sections of the former Motor Vehicle Information and Cost Savings Act or the National Traffic and Motor Vehicle Safety Act are missing from the AIAM database. In contrast, the GM database includes the majority of these interpretations.

The format of the interpretations in the AIAM database is similar to the format used in the Chief Counsel's database, and the letters in the file reference the names and addresses of the persons requesting the interpretations. The AIAM database contains only interpretation letters.

The format of the letters in the GM database differs from that used in the other databases. In addition to interpretation letters, the GM database contains many of the letters that requested the interpretations. In some instances, the requesting letter and the interpretation itself are included in the same file. In other cases, they are in separate files, with a header referring the reader to the corresponding request or interpretation.

The substantive content of the letters in both the AIAM and GM databases appears to be accurate based on an inspection of a random sample of letters. Some words, however, are misspelled or omitted and some of the letters are dated incorrectly. Consequently, once you find a letter in either the AIAM database or the GM database that is germane to the issue you are attempting to resolve, you should verify the content of the interpretation by comparing it with the corresponding interpretation included in the other database.

A WORD OF CAUTION

In attempting to use these interpretations to resolve a question, please be aware that they represent the views of the Chief Counsel based on the facts of individual cases at the time the letter was written. Further, interpretations that are relevant to your situation may not be available on the web site. Consequently, if you are aware of a previous interpretation that appears to address your question, please cite that interpretation and present your question to the Chief Counsel. Do not assume that the interpretation applies to your situation. Critical factual differences may exist between your situation and those addressed in previous interpretations. Further, the Agency's standards and regulations change from year to year, and past interpretations may no longer be applicable.

Written requests for interpretations should be addressed to:

Phone: (202) 366-9511; FAX: (202) 366-3820

You may also send an interpretation request by filling out the form at: http://www.nhtsa.dot.gov/email.cfm