17-1 Division 17
SIGNALS AND INTELLIGENT TRANSPORTATION SYSTEMS 1700 -1 DESCRIPTION Furnish, install, modify and remove signals, flashing beacons, intelligent transportation systems, electrical systems and provisions for future systems. 1700 -2 MATERIAL Refer to Division 10. Item Section Electrical Service Equipment 1098 -1(H) Electrical Materials 1091 Furnish m aterial, equipment and hardware under this section that is pre-approved on t he ITS and Signals QPL available on the Department’s website. 1700 -3 CONSTRUCTION METHODS
A.General Before beginning signal work, verify all existing signal equipment is in satisfactory working order. Report all defective signal equipment to the Engineer so as not to be held responsible for defects. Locate existing conduit, cable runs, inductive detection loops, lead- in cable, junction boxes and detection equipment before installing or using equipment that can damage or interfere with such facilities. The locations of existing inductive detection loops shown in the plans are approximate. Locate all underground utilities before beginning drilling, digging or trenching operations. Ensure that an IMSA certified, or equivalent, Level II traffic qualified signal technician is standing by to provide supervision and emergency maintenance services whenever work is being performed on traffic signal controller cabinets and traffic signal controller cabinet foundations. Stand by status is de fined as being able to arrive, fully equipped, at the work site within 30 minutes ready to provide services. Immediately cease work and notify the Engineer and affected owners if damage to existing utilities, cables or equipment occurs. Make all required repairs and replacements .
B.Regulations and Codes Comply with NCGS § 87, Article 4, Electrical Contractors . Comply with all regulations and codes imposed by the owner of affected utility poles. Notify the Engineer, local traffic law enforcement agency, local utility company and affected railroad companies 7 business days before operational shutdowns to coordinate connection or disconnection to an existing utility or system. Install standoffs, meter bases and service disconnects as required by the NESC, NEC , local utility companies and local ordinances.
17-2 (C) Utility Services
Coordinate all work to ensure electrical power of proper voltage, phase, frequency and ampacity is available to complete the work. Use electrical services cables with THW N insulation. When electrical, telephone and telecommunication service is not furnished by the Department and is required, contact the utility company and make application to ensure all work can be completed. Obtain authorization for service in the Department’s name and make application for service in the Department’s name along with the associated NCDOT Asset Inventory Number shown in the contract. Notify the Engineer im mediately if this number is not shown in the contract. The Department will be responsible for direct payment of monthly utility company usage charges. The Contractor will be responsible for all expenses associated with utility installation costs, hookups, etc.
D.Maintenance and Repair of Material Furnish the Engineer with the name and telephone number s of the supervisory employee who will be responsible for maintenance and repair of equipment during all hours. Maintain and repair all signal and communications related equipment within the project construction limits until completion of the observation pe riod in accordance with Subarticle 1098 -1(C) and receipt of written notification of final acceptance of the project. For all failures, malfunctions or damages to equipment, begin necessary repairs within 4 hours of notification. Complete repairs within 8 hours of notification. Comply with Section 150 for maintenance of traffic flow. The inability to contact the supervisory employee or prearranged alternate will not extend repair time requirements. Remove and replace all signal and communications related equipment that fails. The Department will furnish the Contractor replacement equipment for Department -furnished equipment that fails. Except for damages and malfunctions caused by the Contractor’s work activities, the Contractor will not be held responsible for pre -existing conditions reported to the Engineer before starting traffic signal work at the specific intersection. The Contractor will assume responsibility for all maintenance and emergency services necessary once traffic signal work has begun at the specific intersection and for all damages and malfunctions caused either directly or indirectly by the Contractor’s work activities. Perform maintenance (testing) on all Traffic Signal Conflict Monitors every 12 months for the life of the project begin ning with the initial test and every 12 months thereafter. Provide the initial test date via the manufacturer’s certification or via testing prior to installation of the conflict monitor at an intersection. Use the ATSI Incorporated Model PCMT -2600 or newer Conflict Monitor Tester or an Engineer approved equivalent. Ensure that the Conflict Monitor Tester is maintained and calibrated per the manufacturer’s recommendation. Provide to the Engineer a copy of the manufacturer’s certification that the Confli ct Monitor Tester is in proper working order before testing the Traffic Signal Conflict Monitors. Perform the test on the Traffic Signal Conflict Monitors per the manufacturer’s recommendation. For each Traffic Signal Conflict Monitor tested, provide 2 dated copies of the test results: one copy for the Engineer and one copy for the traffic signal cabinet. In the event the Contractor fails to perform in accordance with the plans and specifications within the time frame specified, the Department reserves the right to perform maintenance and emergency service necessary to ensure continuous traffic signal operation. Further, all expenses incurred by the Department in implementing this option will be deducted from payment due the Contractor, plus $2,500 liquidated damage per occasion, per day, or any portion thereof, until corrected .
17-3 (E) Inspections
The Department may access the Contractor’s equipment to perform railroad, signal and preventative maintenance inspections or conflict monitor certification as necess ary. The Contractor shall be present for these inspections.
F.Removal of Existing Equipment and Material Remove all Department -owned signals and communications related equipment and material that will not be used. Assume ownership of removed poles, messenger cable, interconnect cable, communications cable and supporting hardware , unless otherwise specified . Return all other equipment and material between 8:00 a.m. and 12:00 p.m., Monday through Thursday, to the Traffic Services Office within the Division r esponsible for administration of the project.
G.Railroad Preemption Where railroad preemption is required, coordinate all work with the railroad company. Do not place signals into operation until signal equipment has been interconnected with required railro ad-highway crossing devices and railroad preemption is working properly. Ensure preemption sequences begin immediately after activation of train detection. Contact and coordinate with the railroad company to schedule interconnection of the signal to the r ailroad controller cabinet. Install lead -in cable from the signal controller cabinet to a railroad company furnished and installed lockable junction box. Interconnection will be made by the railroad company. Provide fail -safe operation such that removal of voltage from the railroad side of the isolation relay will initiate the railroad preemption sequence.
H.Vehicle Preemption Systems Where required, implement and install vehicle preemption systems. Coordinate vehicle preemption work with the proper operat ing authority. Contact the proper operating authority and schedule installation of preemption equipment.
I.Timing of Signals Implement timing values for signal controllers. Modify proposed phasing and timing of existing controllers . Reinstall all existing time -based coordination. M ake modifications to existing coordination to account for changes in signal phasing as directed by the Engineer . The Department reserves the right to make or have the Contractor make, field timing changes n ecessary for pattern optimization and to eliminate identifiable, potential hazards to the motoring public. The Engineer will notify the Contractor of timing changes made.
J.Wire and Cable For installation in a conduit system, lubricate cable and wires befor e installing in conduit. Use lubricant that will not physically or chemically harm cable jacket, wire insulation or conduit. Terminate all electrical wire and cable at recessed -screw or barrier type terminal blocks. Unless specifically allowed, connect n o more than 2 conductors to the same terminal screw. Splice electrical wire and cable in junction boxes or condulets as shown in the Roadway Standard Drawings . Maintain color coding of wires through out each splice. Protect ends of wire and cable from wate r and moisture.
K.Electrical Service and Grounding Where electrical services do not include an external electrical service disconnect, modify
17-4 service to include electrical service disconnect and a new grounding electrode system.
Provide a grounding electrode system at all new electrical services. All grounding and bonding equipment shall conform to UL Standard 467. Permanently bond grounding conductor to ground rod using an irreversible ground connector. Unless the irreversible ground connectors are designed for use with more than one conductor, only one conductor shall be used with each irreversible ground connector. Ensure all irreversible ground connectors are installed per manufacturer’s installation instructions. Irreversible compression ground conne ctors requiring the use of a die for installation shall be made using a hydraulic, power, or ratcheting type crimper with appropriate dies. The use of handheld pliers for crimping irreversible compression ground connectors is prohibited. Modify existing electrical services, as necessary, to meet the grounding requirements of the NEC, specifications , plans and test requirements . Remove any ground rods in the cabinet foundation and install a new grounding electrode system. Cut off abandoned ground rods in the cabinet foundation flush with the foundation surface. In addition to NEC requirements, test grounding electrode resist ance for a maximum of 20 ohms. Furnish and install additional ground rods to grounding electrode system as necessary to meet the specifications, plans and test requirements. Grounding electrode resistance test shall be verified or witnessed by the Engine er or the Engineer’s designated representative. Follow test equipment’s procedures for measuring grounding electrode resistance. When using clamp- type ground resistance meters, readings of less than one ohm typically indicate a ground loop. Rework bonding and grounding circuits as necessary to remove ground loop circuits and retest. If a ground loop cannot be identified and removed to allow the proper use of a clamp- type ground resistance meter, use the three- point test method. Complete Inductive Loop & Grounding Test Form available on the Department’s website and place one copy in the traffic signal cabinet . For ease of inspection, the top of ground rods shall be 12 inches (± 1 inch) below finished grade and shall remain exposed until electrical inspecti on is complete. Provide a length of marker tape 6 inches below finished grade directly over grounding electrodes and conductors. For ground rods installed in areas where the slope is greater than 4:1, the top of the ground rods shall be a minimum of 24 inches below finished grade. Pr ovide a length of marker tape 6 inches to 12 inches below finished grade directly over grounding electrodes and conductors.
L.Electrical Bonding Using an approved termination means, connect a # 14 AWG minimum, 19- strand copper conductor (Type THW N) with green insulation to serve as an equipment grounding conductor to metal poles, vehicular and pedestrian signal pedestals and other metallic components . Use messenger cables on wood poles and metal strain poles to provide effective ground fault current path to cabinet ground.
M.Traffic Signal Activation Prior to placing signal in the steady (stop- and-go) mode , the signal should be placed in the flashing mode for up to 7 days or as directed by the Engineer. The signal should not be placed in the steady (stop- and-go) mode on a Saturday or Sunday without prior approval from the Engineer. Do not place the signal in steady (stop -and-go) mode until inspected and without prior approval of the Engineer.
Source: North Carolina Standard Specifications for Roads and Structures, 2024 Edition. Pages 799–802 of 857.