Mr. G. Brandt Taylor
Day-Night Mirrors, Inc.
36 Barnes Hill Road
Berlin, MA 01503

Dear Mr. Taylor:

This responds to your letter asking about the requirements applicable to multiple reflectance mirrors in Federal Motor Vehicle Safety Standard (FMVSS) No. 111, Rear View Mirrors. You stated that your mirror can change its reflectivity either by mechanically rotating a shaft or by actuating an electrical motor.

By way of background information, the National Highway Traffic Safety Administration (NHTSA) has the authority to issue safety standards for new motor vehicles and new items of motor vehicle equipment. NHTSA does not, however, approve or certify any vehicles or items of equipment. Instead, each manufacturer is responsible for "self-certifying" that its products meet all applicable safety standards. The agency periodically tests vehicles and items of equipment for compliance with the standards.

FMVSS No. 111 specifies requirements for the performance and location of rearview mirrors. Section S11, which specifies requirements for mirror construction, provides in relevant part that

All single reflectance mirrors shall have an average reflectance of at least 35 percent. If a mirror is capable of multiple reflectance levels, the minimum reflectance level in the day mode shall be at least 35 percent and the minimum reflectance level in the night mode shall be at least 4 percent. A multiple reflectance mirror shall either be equipped with a means for the driver to adjust the mirror to a reflectance level of at least 35 percent in the event of electrical failure, or achieve such reflectance automatically in the event of electrical failure.

You asked several questions about the requirement for adjusting the mirror in the event of electrical failure. You first asked if a manual override knob could be removable. You then asked whether a removable manual override could be supplied by the car manufacturer along with the car keys or with the owner's manual for insertion into the mirror and use only in the event of an electrical failure. You also asked about whether "west coast" mirrors and mirrors on trailer trucks could have a removable manual override.

The answer to each of your questions is that a removable manual override knob would not be permitted. In the preamble to the final rule amending the mirror construction requirements in FMVSS No. 111, NHTSA stated that the agency's goal is to assure that multiple reflectance mirrors are capable of providing adequate images at all times during the vehicle's operation, including electrical failure situations where the mirror is unpowered. (see 56 FR 58513, November 20, 1991)

The manual override knob you discuss would serve as the means for the driver to adjust the mirror's reflectance level. However, a removable manual override knob would not always serve this purpose, since it would not necessarily always be with the mirror. We are concerned that a removable override device may become lost or otherwise not available when a mirror's reflectance needs to be adjusted. Accordingly, since the agency's goal of providing adequate images at all times during the vehicle's operation would only be achieved by requiring this device to be permanent, a removable override would not be permitted.

I hope this information is helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992.


Philip R. Recht Chief Counsel

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