(a) Sizes of street signs shall be as follows:
(1) Standard size: secondary, rural and subdivision streets.
A. The name plate shall be six inches in width.
B. The letter size and type shall conform to “Standard Alphabets for Highway Signs,” Series C, of the Bureau of Public Roads, and shall be four inches high for the street name and two inches high for abbreviation of the right-of-way designation. The letter series of the street name may be reduced from C to B if the use of Series C would require a sign blank longer than forty-two inches.
C. The blank length to be used for a given street name shall be the shortest length on which the name will fit when four-inch letters are used, except that the length shall be a minimum of twenty-four inches. The maximum blank length will be forty-two inches, unless otherwise approved by the Director.
(2) Oversize: primary and other major secondary roads.
A. Major secondary roads shall be as designated by the Director.
B. The name plate shall be nine inches in width.
C. The letter size and type shall conform to “Standard Alphabets for Highway Signs,” Series C, of the Bureau of Public Roads, and shall be six inches high for the street name and three inches high for abbreviation of the right-of-way designation. The letter height of the street name may be reduced from six inches to five inches when the use of six-inch letters would require a sign blank longer than forty-eight inches.
D. The blank length to be used for a given street name shall be the shortest length on which the name will fit when six-inch letters are used, except that the length shall be a minimum of thirty inches. The maximum blank length shall be forty-eight inches, unless otherwise approved by the Director.
(b) The blank name plate will be of the extruded type and consist of aluminum alloy, A.S.T.M. 2098-6063-T6, or its equivalent, treated with Alodine 1200 chemical conversion coating process, or its equivalent. The extruded blank name plate shall have a web of thickness of 0.090 and a flange thickness of 0.250, and each corner of the name blank shall be square cut. Holes shall be placed in the blank name plate as detailed in Drawing A following the text of this chapter.
(c) The sign background shall be blue sheet reflective material, and letters shall be silver reflective sheeting, 3M brand, or its equivalent, conforming to the specifications for “Encapsulated Lens Reflective Sheeting for Traffic Control Signs,” as specified in the Virginia Department of Transportation's “Road and Bridge Specifications”, Section 701.02(e), and as specified in Federal Specification LS300C, Reflectivity 2, and conforming to specifications on file with the County Director, or an approved equal. The specification on file contains a sheeting manufacturer's field performance and replacement obligation. The reflective material shall be applied to both sides of the treated blank name plate with mechanical equipment in a manner specified by the sheeting manufacturer. The sign background shall be comprised of not more than one piece of reflective sheeting. Reverse screen process color method of fabrication is acceptable, provided that only process colors approved by the sheeting manufacturer are used. Screen process colors must be clear coated.
(d) Sign posts shall be of fourteen gauge galvanized two-inch sheet tube. The base unit will be of twelve gauge galvanized two and one-fourth inch by two and one-fourth inch steel tubing. The base unit will be installed twenty-seven inches in ground with a maximum of three inches above the ground to mount the two-inch by two-inch post, as detailed in Drawing B following the text of this chapter. The signs shall be nonrotating.
(e) The extruded street name plates shall be mounted to the sign post by means of a post to sign (post top) bracket and sign to sign (cross) bracket made of high strength die-cast aluminum alloy number 380 having a tensile strength of 49,000 psi. The post top and cross brackets shall have two angled gussets on ribs on each side for extra strength and shall be smoothly finished and free of holes, pits or flaws. Each set of brackets shall be drilled and tapped to receive six, each, 5/16 - 18-1/2 inch twelve-point spline head bolts, and four, each, 5/16 - 18-3/8 inch hex-head set screws with 5/32 inch center pin, made of either stainless steel, zinc or cadmium plated steel. Post top and cross brackets shall be cast or machined to receive extruded blades with a 0.090 web and a 0.250 flange thickness. Six vandalproof twelve-point spline head bolts and four hex-head set screws with center pin shall be furnished with each set of brackets. The complete unit shall be rigidly fastened together and shall be theft proof when fastened to the post.
(f) The shorter name plate sign shall be mounted above the longer name plate in the assembly.
(g) The bottom of the lowest street name plate shall be ten feet above ground level, except at signalized intersections. At signalized intersections, the bottom of the lowest street name plate shall be at least sixteen feet above ground level, detailed in Drawing B and Drawing C following the text of this chapter.
(h) At signalized intersections, street name signs for both streets will be installed on all vertical supports for traffic signals. Signs will be mounted with standard aluminum cantilevered pole mounted street name brackets as herein provided:
(1) The brackets shall be cast of high-strength aluminum alloy or an approved noncorrosive alternative, degreased, tumbled and polished to a low-sheen smooth finish to ensure resistance to the accumulation of dirt and weather-borne deposits which might wash down upon the street name sign blades and cause premature defacement of the sign.
(2) The brackets shall be “L” shaped in design, with one leg of the L being seven and one-fourth inches long and intended for attachment to the upright support, and the other leg being fourteen and one-half inches long and intended to cantilever out from the support to provide bracing for the sign against both vertical and lateral forces. The design of the bracket shall make it suitable either for nailing, screwing or banding to wood supports, or for bolting or banding to metal supports. The leg for attachment to the support shall be equipped with three-eighths inch holes one- inch on center, or multiples thereof, to match standard spacing of holes in channel posts.
(3) The bracket shall be designed to accept and support the sign in the angle of the L, and each leg of the L shall have an integrally cast block, containing a vertical slot with minimum dimensions one inch long, one inch deep and 0.140 inch wide for securing the sign blade to the bracket.
(4) The sides of all slots shall be solid metal with two holes per slot (both on the same side of the same slot), drilled and tapped to accept two special sawtooth heat-treated plated steel fasteners 5/16 inch - 18UNC-2B for securing the sign blades against removal from the slogs by vandalism and to minimize fatigue failures in the sign blade resulting from wind vibration. The side of each slot opposite the set screws shall be case or machined accurately vertical to ensure that, when installed, the sign assembly will not appear to be bent or askew.
(i) For examples of standard details, see Appendix I, Drawings A through C, at the end of this chapter.
(Ord. 92-01. Passed 1-21-92.)