Current through Register Vol. 47, No. 11, December 11, 2024
Rule 571-41.8 - Specifications for waterway markers(1) The size of a display area shall be as required by circumstances, except that no display area shall be smaller than 1 foot in height. The size shall increase in increments of 6 inches; provided, however, that this specification for increase in increments shall not apply to markers in existence prior to the adoption of this rule.(2) The thickness of the symbol outline shall be one-tenth of the height of the display area.(3) The outside width of the diamond, the inner diameter of the circle, and the average of the inside and outside widths of a square shall be two-thirds of the display area height.(4) The sides of the diamond shall slope at a 35 degree angle from the vertical on a plane surface. Appropriate adjustments for curvature may be made when applied to a cylindrical surface.(5) Materials. Waterway markers shall be made of materials which will retain, despite weather and other exposures, the characteristics essential to their basic significance, such as color, shape, legibility and position. Reflectorized materials may be used.Iowa Admin. Code r. 571-41.8