Section 4189. Traffic Signal Equipment
1. General.
a. Cable Hooks: Unless otherwise specified, provide four galvanized steel cable hooks with a minimum diameter of 3/8 inch and a minimum length of 5 inches.
b. Granular Base: Comply with the following gradations; however, the Engineer may authorize a change in gradation, subject to materials available locally at the time of construction.
|
Table 4189.01-1: Granular Base Gradation |
|
|
Sieve |
Percent Passing |
|
2” |
100 |
|
1 1/2” |
80 to 90 |
|
1” |
15 to 20 |
|
3/4” |
0 to 0.5 |
c. Cover: Include “TRAFFIC SIGNAL” as a message on the cover. Alternate messages may be required as specified in the contract documents.
2. Precast Concrete Handhole.
a. Pipe: Use Class 2000D (Class III). Four, 8 inch knockouts (conduit entrance points) equally spaced around the handhole.
b. Casting: Gray cast iron and certified according to requirements of AASHTO M 306 for a 16,000 pound proof-load (HS-20).
3. Composite Handhole and Cover: Composed of mortar consisting of sand, gravel, and polyester resin reinforced by a woven glass fiber mat or of resin mortar and fiberglass. Ensure the handhole and cover has a minimum ANSI/SCTE 77 2017 Tier 15 rating. Provide a skid resistant surface on the cover. Provide two 3/8-16 UNC stainless steel hex head bolts with washers.
4. HDPE Handhole and Cover.
a. Size: Provide handhole and cover with minimum inside diameter of 24 inches and minimum 24 inches in depth. Handhole to be conical in shape with taper from bottom to top.
b. Loading: Ensure handhole, extensions, and cover comply as a complete unit with ANSI 77 with a minimum Tier 15 rating.
c. Resin: HDPE resin to comply with ASTM D790 for minimum flexural modulus of 142,000 psi and ASTM D638 for minimum yield strength of 3100 psi when using a Type IV specimen, 2 inch per minute test speed, and 0.075 inch thick molded sample.
d. Cover: Ensure cover has skid resistant surface meeting PROWAG requirements with stainless steel bolts meeting manufacturer’s requirements. Ensure cover fits handhole to meet PROWAG vertical surface discontinuity requirements when placed in pedestrian walkways.
1. General.
a. Furnish weatherproof fittings of identical or compatible material to the conduit. Use standard factory elbows, couplings, and other fittings.
b. Use a manufactured conduit sealing compound that is readily workable material at temperatures as low as 30°F and will not melt or run at temperatures as high as 300°F.
c. Furnish flat polyester pull tape with a minimum pulling strength of 1250 pounds and permanent sequential footage markings.
2. Steel Conduit and Fittings.
a. Comply with ANSI C80.1.
b. Use weatherproof expansion fittings with galvanized, malleable iron, fixed and expansion heads jointed by rigid steel conduit sleeves. As an option, the fixed head may be integral with the sleeve, forming a one piece body of galvanized malleable iron.
c. Provide steel bushings.
3. Plastic Conduit and Fittings.
a. PVC.
1) PVC Schedule 40
plastic conduit and fittings complying with NEMA TC-2 (pipe), NEMA TC-3
(fittings), and UL 651 for Schedule 40
heavy wall type 80.
2) Solvent welded, socket type fittings, except where otherwise specified in the contract documents.
3) Threaded adaptors for jointing plastic conduit to rigid metal ducts.
4) Provide bell end fittings or bushings.
b. HDPE.
1) Comply with ASTM F 2160 (conduit) and ASTM D 3350 (HDPE material), SDR 13.5.
2) Use the color specified in the latest NEC or approved by the Contracting Authority.
3) Continuous reel or straight pieces to minimize splicing.
4) For dissimilar conduit connections, provide an adhesive compatible with both materials.
C. Wiring and Cable: Provide wire that is plainly marked on the outside of the sheath with the manufacturer's name and identification of the type of the cable.
1. Power Cable: Comply with Article 4185.11.
2. Signal Cable: Comply with IMSA Specifications 19-1 (PVC jacket) or 20-1 (PE jacket) for PE insulated, 600 volt, solid, multi-conductor copper wire, No. 14 AWG.
3. Tracer Wire: Comply with No. 10 AWG, single conductor, stranded copper, Type thermoplastic heat and water resistant, nylon-coated (THWN), with UL approval, and an orange colored jacket.
4. Ethernet Cable: Provide outdoor use rated cable. Provide either Category 5E (CAT5e) or Category 6 (CAT6) cable.
5. Fiber Optic Cable and Accessories:
a. Furnish fiber optic cable of the mode type, size, and number of fibers specified in the contract documents, and all associated accessories.
b. Meet the latest applicable standard specifications by ANSI, Electronics Industries Association (EIA), International Telecommunication Unit (ITU), and Telecommunications Industries Association (TIA).
c. Multimode Fiber.
· Core Diameter: 62.5 μm ± 1.0 μm
· Cladding Diameter: 125.0 μm ± 1.0 μm
· Core Concentricity: ± 1%
· Max. Attenuation: 3.50 dB/km @ 850 nm
d. Single-Mode Fiber: Meet attributes of ITU-T G.652.D Table 2 and/or ITU-T G.657.A1 for low loss bend as specified in the contract documents.
e. Glass reinforced plastic rod central member designed to prevent the buckling of the cable. Cable core interstices filled with water blocking tape to prevent water infiltration. Dielectric fillers may be included in the cable core where needed to lend symmetry to the cable cross-section.
f. Buffer tubes of dual layer construction with a polycarbonate inner layer and polyester outer layer. Each buffer tube filled with a water-swellable yarn or tape. Buffer tubes stranded around the central member using reverse oscillation or “SZ” stranding process. Gel-free cable and buffer tubes.
g. Buffer tubes and fibers meeting TIA/EIA-598A, “Color coding of fiber optic cables,” with 12 fibers per buffer tube.
h. Cable tensile strength provided by a high tensile strength aramid yarn and/or fiber glass.
i. Dielectric cables, without armoring, or armored cables with corrugated steel tape armor as specified in the contract documents. Outer jacket of medium density polyethylene applied directly over the tensile strength members and flooding compound. Jacket or sheath marked in a contrasting color with the manufacturer's name and the words “Optical Cable,” the year of manufacture, and sequential meter or feet marks. Additionally, provide a durable weather proof label on the cable jacket showing the actual attenuation of each fiber expressed in dB/km.
j. Cable fabricated to withstand a maximum pulling tension of 600 pounds during installation (short term) and 135 pounds upon installation (long term).
k. Shipping, storing, and operating temperature range of the cable: -40°F to 158ºF. Installation temperature range of cable: -22ºF to 158ºF.
l. Each fiber of all fiber optic cable tested by manufacturer at the 100% level for the following tests:
· Proof tested at a minimum load of 50 kpsi
· Attenuation
m. Meet the appropriate standard Fiber Optic Test Procedure for the following measurements:
· Fluid Penetration
· Compound Drip
· Compressive Loading Resistance
· Cyclic Flexing
· Cyclic Impact
· Tensile Loading and Bending
n. Make cable ends available for testing. Seal cable ends to prevent moisture impregnation.
o. Fiber Distribution Panel: Provide a fiber distribution panel capable of terminating the number of fibers as specified in the contract documents.
p. Fiber Optic Connectors.
1) ST type connectors of ceramic ferrule and physical contact end finish to terminate multi-mode fibers to equipment.
2) SC type connectors of ceramic ferrule and physical contact end finish to terminate single-mode fibers to equipment.
3) ST or mechanical connectors not allowed for cable splices.
4) Maximum attenuation per connector: 0.75 dB.
q. Fiber Optic Jumpers/Patch Cords: For connections in the cabinet, provide factory-assembled duplex pigtail jumpers with dielectric strength member, durable outer jacket and ST or SC compatible connectors. Provide adequate length for connections and 2 feet minimum slack.
r. Fiber Optic Breakout Kits: Provide breakout kits for separation and protection of individual fibers, with buffering tube and jacketing materials suitable for termination of the fiber and fiber optic connector.
s. Splices/ Splice Enclosures: Fusion splice continuous fiber runs or branch circuit connections in splice enclosures as allowed or specified in the contract documents. Provide environmentally protected outside plant splice enclosures with adequate number of trays to splice all fibers. Do not splice continuous fibers unless physical restraints require all fibers to be cut, unless approved by the Engineer. Maximum attenuation per splice: 0.3 dB.
1. Use Class C structural concrete complying with Section 2403.
2. Use uncoated
reinforcing steel complying with Article 4151.03. All reinforcing steel
shall be Grade 60.
3. For drilled-shaft foundations, comply with Articles 2433.01, 2433.02, 2433.03,A and 2433.03, C through I.
1. Ground Rods: Provide 5/8 inch by 8 foot copper clad, steel ground rod at each pole and controller footing.
2. Bonding Jumper or Connecting Wire: Provide No. 6 AWG bare conductor, copper wire.
A. Inductive Loop Vehicle Detector: A detector consists of a conductor loop or series of loops installed in the roadway, lead-in (feeder) cable, and a sensor (amplifier) unit with power supply installed in a traffic signal controller cabinet.
1. Cables:
a. Tube Loop Detector Cable: Comply with IMSA Specifications 51-5.
b. Preformed Loop Detector Cable: As approved by the Engineer.
c. Loop Detector Lead-in Cable: Comply with IMSA Specifications 50-2.
2. Detector Loop Sealant:
a. Use a rapid cure, high viscosity, liquid epoxy sealant formulated for use in sealing inductive wire loops and leads embedded in pavement. Ensure the cured sealer is unaffected by oils, gasoline, grease, acids, and most alkalis.
b. Use a sealant complying with Materials I.M. 491.18.
3. Sensor (Amplifier) Unit:
a. Use a sensor unit that is solid state, digital, providing detection channel(s) with an inductance range of 0 to 2000 micro-henries. Output circuits of the sensor unit will be provided by relays. Vehicle presence will result in a continuous call indication.
b. Provide a sensor unit with the following qualities:
1) Sensitivity adjustment to allow as a minimum the selection of high, medium, or low sensitivity.
2) Be capable of providing reliable detection of all licensed motor vehicles.
3) Provide an indicator light for visual indication of each vehicle detection.
4) Will not require external equipment for tuning or adjustment.
5) Provide operation in the pulse mode or presence mode. Ensure mode switch is readily accessible.
6) Provide a self tuning system that is activated automatically with each application of power. Provide automatic and continuous fine tuning to correct for environmental drift of loop impedance.
7) Provide for fail-safe operation (continuous call) in the event of detector loop failure.
8) Ensure each detector channel will respond to a frequency shift in an increasing or decreasing value as occurs with temperature shifts in the pavement without requiring a locked call.
9) Use detector units with delay and extension timing. The delay feature is selected and adjusted externally on the sensor unit housing. Digitally derived timing is selectable in 1 second increments from 0 to 30 seconds. Ensure delay timing inhibits detector output until presence has been maintained for the time selected. Restart delay timer at each new detection.
10) Use a sensor unit capable of normal operation without interference and false calls between sensor units ("crosstalk") when installed in the physical environment of the controller cabinet and the electrical environment of the associated electronic equipment installed therein, including other detectors.
B. Pedestrian Push Button Detectors.
1. Assembly.
a. Ensure the entire assembly is weather tight, secure against electrical shock, withstands continuous hard usage.
b. Provide a removable contact assembly mounted in a die cast aluminum case.
c. Ensure contacts are normally open with no current flowing except at the moment of actuation.
d. Ensure the contacts are entirely insulated from the housing and operating button with terminals for making connections.
e. Provide housing with one outlet for 1/2 inch pipe.
2. Accessible Pedestrian Signals (APS) Push Button Stations.
a. Housing: Die cast aluminum, weather tight, secure against electrical shock and withstands continuous hard usage.
b. Audible and Vibrotactile Features: Audible walk indication tone, vibrotactile arrow, and locator tone complying with MUTCD.
c. Voice Messages: As specified in the contract documents and per MUTCD.
d. Speaker: Weatherproof with automatic volume adjustment to 5 dBA over ambient sound. Maximum volume 100 dB at 3 feet.
e. Push Button: Nonrusting metal alloy, ADA compliant, 2 inch diameter with tactile arrow and 3 pounds maximum operational force.
f. Switch: Solid state rated at 20 million operations minimum.
g. Program and Audio File Updates: USB or Ethernet.
h. Operating Temperature: -30ºF to 165⁰F.
3. Solid State Pedestrian Push Buttons (non-APS).
a. Housing: Die cast aluminum, weather tight, secure against electrical shock and withstands continuous hard usage.
b. Push Button: Nonrusting metal alloy, ADA compliant, 2 inch diameter with 3 pounds maximum operational force, with momentary LED visual confirmation and audible tone confirmation.
c. Switch: Solid state piezo-driven,rated at 20 million operations minimum.
d. Operating Temperature: -30ºF to 165⁰F.
4. Signs: Furnish signs complying with MUTCD.
C. Video Detection Camera System: Detects vehicles by processing video images and providing detection outputs to the traffic signal controller.
1. Video Detection System and Processors.
a. Processor to be card rack mounted, shelf mounted, or located within camera. Compatible with NEMA TS-1, TS-2, ITE ATC, and Type 170 and 2070 controllers and cabinets.
b. Shall be capable of the following:
1) Shadow rejection without special hardware.
2) Non-impaired operation under light intensity changes.
3) Maintained operation during various weather conditions (e.g. rain, fog, snow).
4) Anti-vibration, 5% rejection based on image change.
5) Ability to select direction of flow parameters.
6) Ability to properly detect directionally.
7) Operate in presence mode with less than 4% error.
c. Provide user-defined detection zone programming via a graphical user interface (GUI) and any necessary equipment for future programming. Store detection zones in non-volatile memory.
d. Comply with NEMA TS-1 and TS-2 environmental and physical standards with an operating temperature of -29°F to 140°F, and 0% to 95% relative humidity.
e. Ensure a factory certified representative from the supplier provides on-site VDS programming and testing.
2. Video Cameras.
a. Meet NEMA-4 or NEMA-6P environmental standards.
b. Use camera cable(s) meeting the manufacturer’s recommendations. Provide a continuous run, without splices, from the camera to the controller cabinet.
c. Camera per Approach or Advance Detection Camera:
1) Provide a charge-coupled device (CCD) image sensor with variable focus color or black and white lens providing a minimum of 4 to at least a 40 degree horizontal field of view.
2) Equipped with internal thermostatically controlled heater and external sunshield.
d. Single Stop Line Detection Camera:
1) Provide a minimum 5 MP image sensor with power over ethernet and a fisheye lens capable of detecting multiple approaches from a single mounting location.
2) Include the ability to count traffic.
3) Provide necessary internal thermostatically controlled heater as needed.
D. Microwave/Radar Vehicle Detectors: Detects all vehicles moving within the field of detection at speeds from 2 to 80 mph.
1. Must be capable of the following:
a. Minimum detection range from 3 to 200 feet for all vehicles.
b. Pattern spread of the detection field no more than 16 degrees.
c. Self-tuning and capable of continuous operation over a temperature range of -35°F to 165°F.
d. Side-fire mount or overhead mount.
e. Detecting directional traffic and the direction user selectable.
2. Microprocessor based using Doppler microwave at an operating frequency of 10.525 GHz.
3. FCC certification and tested to the applicable FCC specifications.
4. Enclosure constructed of aluminum or stainless steel and water resistant.
5. All user operated controls and adjustments must be clearly marked and easily accessible.
6. Relay detection output to the controller with a minimum 5 amp rating and designed to place a constant call to the controller in the event of any failure.
7. Easily accessible indicator showing activation of detection relay.
8. Required wiring as recommended by the manufacturer.
9. Provide mounting hardware for the type of mounting specified in the contract documents and power supply equipment as recommended by the manufacturer.
A. Traffic Monitoring System: Provide as specified in the contract documents including, video camera in dome, dome mounting bracket and hardware, camera controller, cabling from camera to controller cabinet, and all accessories, software, and hardware necessary for a complete and operational system.
1. Pan/tilt/zoom (PTZ) color camera with automatic conversion to monochrome during low light levels, auto focus, auto-iris control, electronic image stabilization, privacy masking and progressive CMOS sensor. Minimum 1920 by 1080 maximum resolution. Minimum optical zoom: 25X. Minimum digital zoom: 12X.
2. Camera system provided in a NEMA 4X or IP66 certified rugged weather-resistant package.
3. Provide all required lightning protection for electronics control, power, and coax video outputs.
4. Operating temperature range: -40ºF to 122ºF.
5. Maximum cable length as specified by camera manufacturer.
6. Provide full 360 degree endless pan and 220 degree tilt under PTZ control.
7. Dome electronics capable of programming a minimum of 64 preset views and nine preprogrammed pattern sequences of preset views. All views selectable by the central office computer or a remote control device.
8. Provide encoder and decoder devices as needed to transmit video over existing or proposed communication systems at 30 frames per second (or more).
9. Provide all necessary rack support devices for video viewing and PTZ control.
10. Provide ability to control PTZ and view video remotely. Includes installing necessary software/programming needed for agency to operate system.
B. Fiber Optic Hub Cabinet: As specified in the contract documents.
C. Wireless Interconnect Network: Provides two-way data communication between the system control software and local traffic signal controllers.
1. Data Transceiver.
a. Utilize a license-free spread spectrum radio frequency (902-928 MHZ) with frequency hopping technology.
b. Completely programmable by software. Furnish software to the Engineer.
c. Built-in diagnostics capabilities.
d. Configurable as master, slave, or repeater with store and forward capability.
e. Maintains user selectable power output levels between 0.1 and 1 watt.
f. Operates with input voltages between 6 VDC and 30 VDC.
g. RS-232 interface with 115.2 kbps capability.
h. Operating temperature of -40°F to 167ºF.
i. Receiver sensitivity of -108 to -110 dBm at 10-6 BER.
j. Protected from power surges.
k. Rack or shelf mounted in controller cabinet and connections for antenna, power, and controller.
2. Antenna.
a. Capable of transmitting and receiving data between intersections.
b. Mount near the top of the signal pole nearest the controller cabinet or as specified in the contract documents. Provide engineer-approved mounting hardware.
c. Connect to transceiver via appropriate cable from pole to signal cabinet in same conduit as traffic signal cable. Conceal cable within a watertight connection at antenna.
4189.04 CABINET AND CONTROLLER.
A. NEMA Controller, Cabinet, and Auxiliary Equipment: Comply with the latest edition of NEMA TS1 or TS2, CalTrans model 2070, or ITE advanced transportation controller (ATC) standards.
1. Controller.
a. Solid state modular design with digital timing and capable of accommodating at least eight phases.
b. Fully prompted, front panel keyboard with menu driven programmability.
c. Local time base scheduler including automatic accommodation for daylight savings time.
d. Local coordination control.
e. Local preemption control with at least four programmable internal preemption sequences.
f. Current software and documentation.
g. Data retained in a memory medium that does not require battery backup.
2. Cabinet.
a. Unpainted aluminum cabinet according to NEMA standards.
b. Aluminum cabinet riser with same dimensions as cabinet and 12 to 18 inch height, as specified in the contract documents.
c. ATC cabinet voltage category as specified in the contract documents.
d. Police door with auto/flash switch and on/off power switch, manual/stop time switch, for signal heads only. Controller to remain in full operation regardless of switch positions.
e. Maintenance panel on inside of the main door containing the following test switches.
1) Controller power switch.
2) Detector test switches.
3) Stop time switch.
4) Signal flash switch.
f. Heavy-duty clear plastic envelope attached to inside wall of cabinet or cabinet door, for cabinet wiring diagrams, 12 inches by 18 inches minimum.
g. GFI electrical outlet and lamp in accessible location near the front of the cabinet. GFI outlet fused separately from main AC circuit breaker. LED cabinet lamp connected and fused with GFI outlet.
h. Back panel positions to accommodate phasing and expansibility specified in the contract documents.
i. Power protection devices including AC power circuit breakers, radio interference suppressors, and lightning and surge protectors.
1) AC field service single pole, nonadjustable, magnetic breaker rated for 117 VAC operation, NEC approved.
2) Radio interference suppressors (RIS) as required to minimize interference in all broadcast transmission and aircraft frequency bands.
3) Lightning arrestor/surge protector capable of withstanding repeated (minimum of 25) 30,000 ampere surges.
j. Neatly train wiring throughout the cabinet and riser. Bundle and attach wiring to interior panels using nonconductive clamps or tie-wraps.
3. Auxiliary Equipment: Conflict monitor/malfunction management unit, flasher, load switches, terminals and facilities, and miscellaneous equipment and materials according to NEMA standards. For ATC cabinets, use serial interface unit, high density switch pack/flasher unit, cabinet monitor unit, cabinet power supply requirements, auxiliary display unit, sensor unit, and miscellaneous equipment materials meeting ITE standards.
B. Uninterruptible Power Supply Battery Backup System: Monitors 120VAC input from the electric utility source and automatically switches to/from a system consisting of batteries and electronics.
1. Include a maintenance bypass switch to allow operation of the traffic signal system while repairs are made to the battery backup system.
2. Designed to provide a minimum of 4 hours of normal operation.
3. Use cabinet equipment that is plug connected and shelf mounted.
4. Designed to cover a temperature range from -30°F to 165°F and include a surge suppressor.
C. Emergency Vehicle Preemption System: As specified in the contract documents.
4189.05 POLES, HEADS, AND SIGNS.
A. Vehicle Traffic Signal Head Assembly: Comply with current MUTCD and ITE standards.
1. Housing.
a. Individual signal sections made of a durable polycarbonate. Use color specified in the contract documents. Color to be an integral part of the materials composition.
b. Self-contained unit capable of separate mounting or inclusion in a signal face containing two or more signal sections rigidly and securely fastened together.
c. Equipped with openings and positive locking devices in the top and bottom so that it may be rotated between waterproof supporting brackets capable of being directed and secured at any angle in the horizontal plane.
d. Doors and lenses with suitable watertight gaskets and doors that are suitably hinged and held securely to the body of the housing by simple locking devices of non-corrosive material. Doors are to be easily removed and reinstalled without use of special tools.
2. Optical System: Designed to prevent any objectionable reflection of sun rays even at times of the day when the sun may shine directly into the lens.
3. Lenses: 12 inch diameter polycarbonate. Do not use glass lenses.
4. Visors.
a. Standard Installation.
1) Each signal lens is to have a visor with the bottom 25% open.
2) Minimum 0.1 inch in thickness and black in color.
3) Fits tightly against the housing door with no filtration of light between the visor and door.
4) Minimum length of 9 1/2 inches. Ensure the visor angle is slightly downward.
b. Optically Programmed Sections: Make sure the optical unit and visor are designed as a whole to eliminate the return of outside rays entering the unit from above the horizontal.
5. Terminal Block.
a. Three-section signal equipped with a six position terminal block.
b. Four- and five-section signal equipped with an eight position terminal block.
6. Backplate.
a. Manufactured one-piece, durable, black plastic or aluminum capable of withstanding a 100 mph wind.
b. Provides 5 inches of black field around the assembly.
c. If specified, provide high visibility reflective tape with a minimum width of 1 inch.
7. Mounting Hardware.
a. Rigid: 1 1/2 inch aluminum pipe and fittings, natural aluminum finish or match the pole color if specified in the contract documents. Secure to pole with a minimum 5/8 inch wide stainless steel banding material.
b. Universally Adjustable: Rigid mounted, consisting of both top and bottom brackets and easily adjustable in both horizontal and vertical planes. Provide galvanized steel cable material per manufacturer’s recommendation.
8. LED Modules: Comply with current ITE standards and consistent with cabinet voltage requirements.
B. Pedestrian Traffic Signal Head Assembly: Comply with current MUTCD and ITE standards.
1. Housing.
a. Made of a durable polycarbonate. Use color specified in the contract documents. Color to be an integral part of the materials composition.
b. Self-contained unit capable of separate mounting or inclusion in a signal face containing one or more signal sections rigidly and securely fastened together.
c. Equipped with openings and positive locking devices in the top and bottom so that it may be rotated between waterproof supporting brackets capable of being directed and secured at any angle in the horizontal plane.
d. Doors and lenses with suitable watertight gaskets and doors that are suitably hinged and held securely to the body of the housing by simple locking devices of non-corrosive material. Doors are to be easily removed and reinstalled without use of special tools.
2. Visor.
a. Egg crate or tunnel type visor, as specified in the contract documents, attached to the housing door by stainless steel screws or according to manufacturer’s requirements.
b. Fit tightly against the housing door to prevent any filtration of light between the door and the visor.
c. Ensure the visor angle is slightly downward.
3. LED Module.
a. Provide a LED unit(s) for the filled upraised hand symbol, walking person symbol, and countdown timer.
b. Ensure immediate blank out of the countdown timer display upon recognizing a shortened “Walk” or a shortened "Flashing Don't Walk" interval.
c. Comply with current ITE standards and consistent with cabinet voltage requirements.
C. Traffic Signal Poles and Mast Arms.
1. General.
a. Use mast arm length and vertical pole height as specified in the contract documents.
b. Ensure the mast arms, poles, and supporting bases are galvanized on both interior and exterior surfaces according to ASTM A 123.
c. Use continuously tapered, round, steel poles of the transformer base type for poles with mast arms 60 feet or less. Fabricate poles from low carbon (maximum carbon 0.30%) steel of U.S. standard gauge.
d. For poles with mast arms greater than 60 feet or when a transformer base is not specified, provide a 6 inch by 16 inch handhole in the pole shaft for cable access. Provide a cover for the handhole. Secure the cover to the base with simple tools. Use corrosion resistant hardware.
e. Ensure minimum yield strength of 48,000 psi after manufacture. Supply base and flange plates of structural steel complying with ASTM A 36 and cast steel complying with ASTM A 27, Grade 65-35 or better.
f. Where a combination street lighting/signal pole is specified in the contract documents, ensure the luminaire arm is mounted in the same vertical plane as the signal arm unless otherwise specified. Use a luminaire arm of the single member tapered type. Fabricate the pole with a minimum 4 inch by 6 inch handhole and cover located opposite the signal mast arm.
g. If allowed by the Engineer, poles and mast arms may be fabricated by shop welding two sections together, resulting in a smooth joint as follows:
1) Ensure a minimum of 60% penetration for longitudinal butt welds in plates 3/8 inch and less in thickness, except within 1 foot of a transverse butt-welded joint. Ensure a minimum of 80% penetration for longitudinal butt welds in plates over 3/8 inch in thickness.
2) Ensure 100% penetration for longitudinal butt welds in poles and arms within 1 foot of a transverse butt-welded joint.
3) Ensure 100% penetration for transverse butt welds by using a back-up ring or bar to connect the sections.
4) Examine the full-length of all transverse butt welds and 100% penetration longitudinal butt welds by ultrasonic inspection according to the requirements of ANSI/AWS D1.1.
5) Comply with ANSI/AWS D1.1 except as modified by Article 2408.03, B.
h. For mast arms over 50 feet length, two-piece mast arms with a slip-fit and bolt connection are allowed.
i. Provide non-shrink grout (complying with Materials I.M. 491.13) or a rodent guard (complying with Materials I.M. 443.01) for placement between the pole base and the foundation per the manufacturer’s requirements.
2. Pole Design.
Comply with AASHTO 2013 Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals. Use a 90 mph basic wind speed (3 second gust) with a 50 year mean recurrence interval for strength design. Use Category II for fatigue design. Apply only natural wind gust loads (i.e., do not apply galloping loads, vortex shedding loads, or truck-induced gust loads) for fatigue design. Install vibration mitigation devices that mechanically or statically minimizes vibration on the mast arm caused by the wind on all traffic signal pole mast arms over 60 feet in length as shown in the standard details.
3. Hardware.
Equip poles and mast arms with all necessary hardware and anchor bolts to provide for a complete installation without additional parts.
4. Anchor Bolts, Nuts, and Washers.
Furnish each anchor bolt with one leveling nut, one anchoring nut, and one jam nut (if required) on the exposed end and one of the following on the embedded end: nut, nut and plate, or nut and anchor bolt assembly ring plate. Use anchor bolts, nuts, and washers that comply with Materials I.M. 453.08. Meet the following requirements:
a. Anchor Bolts.
1) Use straight full-length galvanized bolts.
2) Comply with ASTM F 1554, Grade 105, S4 (-20oF).
3) Threads are to comply with ANSI/ASME B1.1 for UNC thread series, Class 2A tolerance.
4) The end of each anchor bolt intended to project from the concrete is to be color coded to identify the grade.
5) Do not bend or weld anchor bolts.
b. Nuts.
1) Comply with ASTM A 563, Grade DH or ASTM A 194, Grade 2H.
2) Use heavy hex.
3) Use ANSI/ASME B1.1 for UNC thread series, Class 2B tolerance.
4) Nuts may be over-tapped according to the allowance requirements of ASTM A 563.
5) Refer to Articles 2522.03, H, 2, b through h for tightening procedure and requirements.
c. Washers.
Comply with ASTM F 436 Type 1.
d. Galvanizing.
Galvanize entire anchor bolt assembly consisting of anchor bolts, nuts, and washers (and plates or anchor bolt assembly ring plate, if used) according to the requirements of ASTM B 695, Class 55 Type 1 or ASTM F 2329 with zinc bath temperature limited to 850°F. Galvanize entire assembly by the same zinc-coating process, with no mixed processes in a lot of fastener assemblies.
D. Traffic Signal Pedestal Poles.
1. Materials.
a. Pedestal: The height from the bottom of the base to the top of the shaft as specified in the contract documents.
b. Pedestal Shaft: Schedule 80 with satin brush or spun finish aluminum tubing. Top of the shaft outer diameter to be 4 1/2 inches and provided with a pole cap. Supply base collar for poles with shaft lengths greater than 10 feet. Provide brackets to mount pedestrian signal on side of pole.
c. Pedestal Base: Cast aluminum, square in shape, with a handhole.
1) Handhole: Minimum of 3 1/2 inches by 5 1/2 inches and equipped with a cast aluminum cover that can be securely fastened to the base with the use of simple tools.
2) Base: A breakaway base with a four bolt pattern uniformly spaced on a minimum of 6 inch diameter bolt circle. Meet or exceed AASHTO breakaway requirements.
2. Anchor Bolts: Four 5/8 inch by 7 1/2 inch steel (minimum), hot dip galvanized anchor bolts complying with ASTM F 1554, Grade 36, meeting pole manufacturer requirements for installation, complete with all hardware required for installation. For pedestal pole sidewalk mounting, provide anchor bolts and hardware per pole manufacturer requirements.
1. Sheet aluminum and retroreflective sheeting complying with Section 4186.
2. Use a universally adjustable mast arm mounted sign bracket.
3. Comply with MUTCD and the contract documents for the street name sign dimensions, letter height and font.