Informational sites for the erection and maintenance of Class 3 and 4 advertising and informational signs may be established in accordance with § 1.35 of this chapter. The location and frequency of such sites shall be as determined by agreements between the Secretary of Transportation and the State highway departments.

Class 3 and 4 signs may be permitted within such informational sites in protected areas in a manner consistent with the following provisions:

No sign may be permitted which is not placed upon a panel.

No panel may be permitted to exceed 13 feet in height or 25 feet in length, including border and trim, but excluding supports.

No sign may be permitted to exceed 12 square feet in area, and nothing on such sign may be permitted to be legible from any place on the main-traveled way or a turning roadway.

Not more than one sign concerning a single activity or place may be permitted within any one informational site.

Signs concerning a single activity or place may be permitted within more than one informational site, but no Class 3 sign which does not also qualify as a Class 4 sign may be permitted within any informational site more than 12 air miles from the advertised activity.

No sign may be permitted which moves or has any animated or moving parts.

Illumination of panels by other than white lights may not be permitted, and no sign placed on any panel may be permitted to contain, include, or be illuminated by any other lights, or any flashing, intermittent, or moving lights.

No lighting may be permitted to be used in any way in connection with any panel unless it is so effectively shielded as to prevent beams or rays of light from being directed at any portion of the main-traveled way of the Interstate System, or is of such low intensity or brilliance as not to cause glare or to impair the vision of the driver of any motor vehicle, or to otherwise interfere with any driver's operation of a motor vehicle.