816Signs and Traffic Devices

Signs and Traffic Devices

816.1Sheet Aluminum for Sign Panels

1 For sign panels, ensure the provision of sheet aluminum made as follows:

retroreflective sheeting;

maintained within limits of operating-solution strength by reliable control methods.

816.2Aluminum Alloy Channels and Tubing

1 Ensure the provision and use of aluminum alloy channels and tubing in accordance with ASTM B 221 [ASTM B 221M] for alloy 6061-T6.

816.3Retroreflectors

1 Ensure the provision and use of a methacrylate lens is accordance with ASTM D 788, grade 8.

2 For delineators or markers, provide retroreflectors consisting of a round, retroreflective unit house in an embossed frame with a single, grommeted mounting hole. Provide lenses that are:

2 [4500 mm 2] of retroreflective surface and

mounting hole to an opaque back to form a unit permanently sealed against dust, water, and water vapor.

3 Ensure the provision and use of a retroreflector housing made:

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retroreflector mounting hole.

816.3.1 Definitions

1 The department will use the following definitions in reference to retroreflectors:

to the face and the direction of light incident on the reflector.

line of sight and the direction of light incident on the retroreflector.

retroreflector with 1 in² [625 mm²] of retroreflecting surface for each lux of illuminance at the retroreflector; this term will be used in reference to optical testing of retroreflectors for letters, symbols, and accessories.

center-mount, 3¼-inch [85 mm] diameter retroreflector for each lux of illuminance at the retroreflector.

816.3.2 Optical Testing

1 Optically test retroreflectors using procedures performed as follows:

with an effective diameter of 2 in [50 mm], operated at normal efficiency.

sensitivity of 1 × 107 foot-candle [1 µlx/mm] of scale division, with a receiver aperture diameter of ½ in [12 mm], and shielded to eliminate stray light.

the aperture, of 2.1 in [55 mm] for an observation angle of 0.1 degree; of 3 ½ in [90 mm] for an observation angle of 0.17 degrees: and of 6.9 in [175 mm] for an observation angle of 0.33 degrees.

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2 If using a test distance other than 100 ft [30 m], modify the source and aperture dimensions and the distance between return light source and aperture in the same proportion as the test distance.

3 Ensure that the specific luminance of crystal retroreflectors for cutout letters, symbols, and accessories is in accordance with or exceeds Table 816.3.2-1, Specific Luminance Requirements: Crystal, measured while retroreflectors are spinning.

Table 816.3.2-1 Specific Luminance Requirements: Crystal Observation Angle (degrees) Entrance Angle (degrees) Specific Luminance fc/in² [cd/m²/lx] 0.1 0 14 [2020] 0.1 20 5.6 [810]

4 For yellow reflectors, ensure a minimum specific luminance equal to 60 percent of the value for crystal.

5 Ensure that the specific intensity of retroreflectors for delineators or markers is in accordance with or exceeds Table 816.3.2-2, Specific Intensity Requirements, measured while the retroreflectors are spinning:

Table 816.3.2-2 Specific Intensity Requirements Observation Angle (degrees) Entrance Angle (degrees) Specific Intensity (fc [cd/lx]) Crystal Yellow 0.1 0 119 [11.1] 71 [6.6] 0.1 20 47 [4.4] 28 [2.6]

6 If more than 4 percent of the samples tested fail to reach the above values, test a resample; the engineer will reject the lot if more than 4 percent of the resample fails.

7 Ensure the provision and use of retrore flectors that have been tested for adequate sealing against dust and water using procedures performed as follows:

of mercury [17 kPa] for five minutes.

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inside the reflector), test a resample; the engineer will reject the lot if more that 4 percent of the resample fails.

8 Give the engineer three copies of the manufacturer’s certification that the retroreflectors provided meet these requirements. When asked, provide at least five samples randomly selected by the engineer from each shipment of each type of retroreflector, at no additional cost to the department.

9 The engineer will approve retroreflectors based on the manufacturer’s certification or tests performed on samples as provided in previous paragraphs.

816.4Retroreflective Sheeting

1 For the type specified, provide and use an encapsulated glass bead, encapsulated prismatic, or nonmetallic, microprismatic reflective material precoated with adhesive backing protected by a treated plastic liner and in accordance with AASH TO M 268 (ASTM D 4956).

816.4.1 Temporary Traffic Control Devices

1 Provide retroreflective sheeting for temporary traffic control devices that meet the minimum requirements as shown in Table 816.4.1- 1, Retroreflective Sheeting Requirements.

Table 816.4.1-1 Retroreflective Sheeting Requirements Traffic Control Device Highway Designation Category I Category II Category III Non-interstate ASTM D 4956 Type III ASTM D 4956 Type III ASTM D 4956 Type III Interstate ASTM D 4956 Type III Fluorescent Orange: ASTM D 4956 Type IV

White: ASTM D 4956 Type III ASTM D 4956 Type III

816.5Metal Delineator Posts

1 Ensure the provision and use of metal delineator posts of the shape specified, rolled from structural steel, rerolled rail steel, or new billet steel with a minimum yield strength of 30,000 psi [210 MPa], minimum ultimate tensile strength of 50,000 psi [340 MPa], and a weight [mass] of at least 1.1 lb/ft [1.64 kg/m] or alternate delineator post with a weight [mass] of at least 2.2 lb/ft [3.27 kg/m]. Ensure that posts have been cleaned and painted with two coats of baked, black enamel.

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2 To attach retroreflectors to posts, provide an open-end blind rivet. For rivet expansion, provide a cadmium-plated steel, break-stem-type mandrel that leaves the mandrel head in the rivet body.

3 When specified, paint the top 6 in [150 mm] of posts with a white or silver retroreflective liquid coating consisting of crystal retroreflective elements suspended in a solvent- dispersed vehicle and with a specific intensity in accordance with Table 816.5-1, Specific Intensity Requirements.

Table 816.5-1 Specific Intensity Requirements Observation Angle (degrees) Entrance Angle (degrees) Specific Intensity (fc/ft² [cd/lx]) 0.2 0 0.85 [9.1] 0.2 15 0.85 [9.1]

816.6Roadway Sign Supports

1 For roadway signs, ensure the provision and use of steel parts, including posts, galvanized in accordance with Subsection 815.14, Galvanized Coating, and Subsection 501.4.1.25, Galvanizing. Ensure the provision of steel pipe in accordance with ASTM A 53 [ASTM A 53M], schedule 40, grade B, and of steel plates and shapes in accordance with ASTM A 36 [ASTM A 36M].

2 For sign posts made of tubular-steel, ensure the use of cold-rolled sheet steel of the gauge specified and in accordance with ASTM A 653 [ASTM A 653M] and ASTM A 924 [ASTM A 924M], grade A, or of hot-rolled carbon sheet steel of the gage specified and in accordance with ASTM A 570 [ASTM A 570M] and with a minimum yield of 60,000 psi [414 MPa]. Ensure that all cold-rolled sheet steel, including connecting hardware, is hot-dipped galvanized in accordance with ASTM A 653 [ASTM A 653M] and ASTM A 924 [ASTM A 924M], coating designation G- 90 [Z275]; if welding after galvanization, zinc-coat corner welds after scarfing.

3 Ensure that post tubing made of hot-rolled carbon sheet-steel is triple-coated with an in- line application of hot-dipped zinc (galvanization). Ensure that the inside surface receives a double in-line application of a full, zinc-based organic coating. If welding occurs after galvanization, zinc-coat corner welds after scarfing.

816.7 O verhead Sign Supports

1 For overhead signs, ensure the provision and use of structural steel shapes and plates in accordance with ASTM A 36 [ASTM A 36M]. Use steel pipe in accordance with ASTM A 53 [ASTM A 53M]—grade B for pipe with a nominal diameter greater than 2 in [50 mm] and type F for smaller diameters. The department will allow the use of pipe

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with the chemical and mechanical properties of ASTM A 36 [ASTM A 36M] and the dimensional tolerances of ASTM A 53 [ASTM A 53M].

816.8Bolts and Fasteners

1 For use with traffic signs and devices, ensure the provision of:

Strength Bolts and Fasteners

Coating.

816.9Plywood Sign Panels and Barricades

1 For sign and barricade panels, ensure the provision and use of high- density overlay (HDO), exterior- grade, B -B, 90 -90, of the thickness specified and in accordance with APA-The Engineered Wood Society standard PS 1-95, or approved equivalent.

816.10Treated-Timber Sign Posts

.1 General

1 Ensure that timber posts for signs are treated in accordance with American Wood Protection Association (AWPA) Standard U1 to the requirements of Use Category 4A

817, Structural Timber and Lumber.

.2 Dimensional Timber Posts

1 Ensure the provision and use of rough-sawn wood cut from live, growing trees of Lodgepole Pine, Ponderosa Pine, Douglas Fir, or Southern Y ellow Pine, graded in accordance with Subsection 817.1, Structural T imber and Lumber, and supplie d in accordance with Table 816.10.2-1, Dimensional Timber Post Grades.

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Table 816.10.2-1 Dimensional Timber Post Grades Post Size Grade 4 in × 4 in [100 mm × 10 mm] No. 1 Structural Light Framing 4 in × 6 in [100 mm × 10 mm] No. 1 Structural Joists and Planks 6 in × 6 in [150 mm × 150 mm] and larger (1) Select Structural Posts and Timbers (1)Rough cut Southern Yellow Pine and Douglas Fir drilled for breakaway are unacceptable. Nominal surfaced Southern Yellow Pine and Douglas Fir drilled for breakaway are acceptable. All other rough cut or surface pine species are acceptable.