Mr. Marvin Lee Eastman
1033 E. Vine
Fresno, CA 93706-5303

Dear Mr. Eastman:

This is in reply to your letter of September 24, 1996, with respect to a "safety display board to be mounted on the rear of a trailer in the effort to help prevent accidents involving cars and tractor trailers." You would like to know if this is permissible under the laws that we administer.

The message board could be mounted on the side (at an angle) or on the rear of the trailer. When the turn signal is activated, a message "will rotate around the message board" which may read "For your safety please move in front of the tractor or to the rear of the trailer."

We appreciate your thoughtful wish to improve safety on our nation's highways, but, in our opinion, your invention may create more problems than it would solve. In order to read and comprehend a moving message, a vehicle operator will be diverted from giving full attention to driving. Furthermore, a flashing turn signal that is used for purposes other than to indicate an intention to turn has the potential to confuse motorists to the front as well as to the rear

of the trailer. For these reasons, we believe that this system could impair the effectiveness of some lighting equipment such as stop lamps and turn signal lamps which we require to be on trailers. When a lamp's effectiveness is impaired, it is equivalent to making that lamp inoperative, in our view.

Under the laws we administer, this system would not be permitted as original equipment on new trailers. In the aftermarket, the system could be marketed for trailers in use, but it could not be legally installed by manufacturers, dealers, distributors, or motor vehicle repair businesses. However, the owner would not be prohibited from installing the message board system. In this event, the legality of the message board becomes a matter of State law. We are unable to advise you on State laws and recommend that you contact the Department of Motor Vehicles in the States in which the system may be used.

If you have further questions, you may refer them to Taylor Vinson of this Office (202-366-5263).

Sincerely,

John Womack
Acting Chief Counsel
ref:108
11/2/96