Article 1 — Description
1.1 Installation . Fabricate, furnish, and install traffic signal detectors.
1.2 Removal . Remove existing traffic signal detectors.
Article 2 — Materials
Provide new materials as shown on the plans and in accordance with this Item and the pertinent requirments of the following Items . Item 618, “Conduit” Item 624, “Ground Boxes” Item 682, “Vehicle and Pedestrian Signal Heads” Item 684, “Traffic Signal Cables”
2.1 Pedestrian Detector . Supply housing or an adapter ( i.e., saddle) that conforms to the pole shape, fitting
flush to ensure a rigid installation. Supply adapters of the same material and construction as the housing. Supply push button switches that have single- pole, single- throw contacts and screw -type terminals and have a design life of at least 1 million operations. Ensure the internal components provide a push button with normal open contacts, and include all electrical and mechanical parts required for operation. Ensure the push button assembly is weather- tight and tamperproof, is designed to prevent an electrical shock under any weather condition, and has provisions for grounding in accordance with the NEC.
2.1.1 Standard Pedestrian Detector . Provide a two-piece cast aluminum housing unit consisting of a base
housing and a removable cover. Provide threaded holes for 0.5- in. conduit in the housing for any necessary conduit attachment. Ensure the manufacturer’s name or trademark is located on the housing.
2.1.2 Accessible Pedestrian Signals (APS) . Provide accessible pedestrian detectors in accordance with
DMS -11132 , “Accessible Pedestrian Signals.”
2.2 Vehicle Loop Detectors. Use stranded copper No. 14 AWG XHHW cross- linked -thermosetting-
polyethylene- insulated conductor rated for 600V alternating current for vehicle detector loop wire unless otherwise shown on the plans. Ensure each length of wire shows the name or trademark of the manufacturer, insulation voltage rating, wire gauge, and insulation type at approximate 2- ft. intervals on the insulation surface. When shown on the plans, use flexible vinyl or polyethylene tubing with 0.184- in. minimum inside diameter, 0.031- in. minimum wall thickness, 0.26- in. maximum outside diameter, and a smooth bore. Use tubing that does not adhere to the loop wire in any way and is capable of resisting deterioration from oils, solvents, and temperatures up to 212° F. Use tubing that is abrasion- resistant and remains flexible from - 22–212° F. Use orange or red tubing unless otherwise shown on the plans. Use sealant for the vehicle detector loops in accordance with DMS -6340 , “Vehicle Loop Wire Sealant.” 945 3. CONSTRUCTION
3.1 Pedestrian Detect or.
3.1.1 Push Button Unit . Install push buttons in accordance with the TMUTCD. Wire the push button in
conformance with manufacturer’s installation instructions. Close unused housing openings with a weather -tight closure painted to match the housing. Verify that each button is communicating and fully functional . Do not use terminal connections or splice wire leads except at approved locations. All allowed splices must be watertight. Attach wires to terminal posts using solderless terminals unless otherwise advised by manufacturer’s recommendations. Attach terminals to the wires using a ratchet -type compression crimping tool properly sized to the wire. Mount a pedestrian push button sign near each push button as shown on the plans. For installations where APS buttons are placed less than 10 ft. apart from one another, program the appropriate speech walk message (include the name of the appropriate street in the message) for these buttons. When two APS buttons are installed on the same pole, ensure that the APS buttons are insulated to eliminate vibrations from traveling to the other button.
3.1.2 Controller Unit . If a controller unit is required by the plans, integrate the pedestrian controller unit into the
traffic signal controller cabinet assembly.
3.2 Vehicle Loop Detecto r. Provide the loop location, configuration, wire color, and number of turns as shown
on the plans. Loops may be adjusted by the Engineer to fit field conditions.
3.2.1 Saw-Cuts . Cut the pavement using a concrete saw to form neat lines. Do not exceed 1- in. depth on concrete
bridge slab saw -cuts. Cut all other saw -cuts deep enough to provide a minimum of 1-in. depth of sealant over the wire. Make a separate saw -cut from each loop to the edge of the pavement unless otherwise shown on the plans. Ensure the cut is clean and dry when the wire and sealant are placed.
3.2.2 Conduit . Place conduit between the pavement and ground box as shown on the plans.
3.2.3 Loop Wire Color . Use the following color code unless otherwise shown on the plans. Use white for the first
loop on the right , followed by black, orange, green, brown, and blue. Use the same color for all loops in the same lane. Loops installed in multi -lanes will have the same color code in the order in which the loops are installed. When facing the same direction of traffic fl ow, the color code will read from right to left for all lanes carrying traffic in that direction. If traffic moves in two directions, the color code will be repeated for the other direction of traffic.
3.2.4 Loop Wire Installation. When shown on the plans, place the loop wire in a flexible vinyl or polyethylene
tubing in accordance with Article 688.2., “Materials.” The loop wire color requirements do not apply to wires in tubing. Twist the wire from the loop to the ground box a minimum of five turns per foot. When only one pair of wires is in a saw -cut, it need not be twisted while in the saw -cut. Do not splice loop wire in the loop or in the run to the ground box. Hold the loop wire in place every 2 ft. with strips of rubber, neoprene flexible tubing, or polyethylene foam sealant approximately 1 in. long. Leave these strips in place and fill the slot with loop sealant. Splice the loop lead- in cable and loop detector wires only in the ground box near the loop it is serving. Use non-corrosive solder for splices and ensure the splice is watertight. Ground the drain wire of the loop lead- in 946 cable to earth ground only at the controller or detector cabinet. Ensure the resistance from the drain wire to the ground rod is less than 1 ohm.
3.3 Installation . Install the detectors as shown on the plans or as directed.
3.4 Removal . Remove the existing item as shown on the plans or as directed. Ensure the items designated for
salvage are removed in a manner to avoid undue stress or damage. When the removed item leaves an opening, cover the opening with similar material to an equivalent condition. When the removed item leaves an unused signal cable, remove the cable. When the removed item leaves unused conductors within a signal cable still in use, trim back and tape off to ensure no electrical shorts by unused conductors .
Article 4 — Measurement
Vehicle loop detector will be measured by the foot of saw -cut containing loop wire installed or removed. Pedestrian push button detector and controller unit will be measured by the each installed or rem oved. This is a plans quantity measurement Item. The quantity to be paid is the quantity shown in the proposal, unless modified by Article 9.2., “Plans Quantity Measurement.” Additional measurements or calculations will be made if adjustments of quantities are required.
Article 5 — Payment
The work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for at the unit price bid for the installation or removal of the “Vehicle Detectors” of the type specif ied, “Vehicle Detector Controller Unit” of the type specified, “Pedestrian Detector Push B utton Units” of the type specified, or “Pedestrian Detector Controller Unit.”
5.1 Installation . This price is full compensation for furnishing, installing, detector hardware and software
configuration, detector testing, detector controller units, saw -cutting, excavation, backfill, sealant, sealant placement , pavement repair associated with saw -cutting, materials, equipment, labor, and incidentals. Conduit and loop wire from the edge of pavement to the ground box used for the vehicle loop detectors will not be measured or paid for directly, but will be subsidiary to this Item. New ground boxes will be paid for under Item 624, and the new loop lead- in cable will be paid for under Item 684.
5.2 Removal . This price is full compensation for removing, salvaging, disassembling, and stockpiling detector
components removed as shown on the plans or as directed. Repairs to the pavement or signal poles required from the removal will be subsidiary to this Item.