Section 2525.  Traffic Signalization

 

2525.01     DESCRIPTION.

This section was developed in conjunction with Section 8010 of the SUDAS Standard Specifications, with modifications to suit the needs of the Department.

 

A.    This section includes furnishing of material and equipment necessary to complete, in place and operational, traffic control signal(s) as described in the contract documents, including:

·         Underground,

·         Detection,

·         Communications,

·         Cabinet and Controller, and

·         Poles, Heads, and Signs.

 

B.    Submittals:  Submit applicable brochures, technical data, catalogs, cuts, diagrams, manufacturer's drawings and installation instructions, samples if required, and other descriptive data including the complete description, trade name, model number, type, size, and rating, as well as the additional requirements listed below. Submit according to Article 1105.03.

 

1.     Schedule of Unit Prices:  Submit a completed schedule of unit prices. Estimates of the work performed on the project will be made by the Engineer and the unit costs will be used to prepare progress payments to the Contractor.

 

2.     Material and Equipment List:  Submit a completed list of materials and equipment to the Engineer for written approval before any equipment or materials are ordered.

 

3.     Contractor Certification:  Submit name(s) and contact information of the IMSA Level II Certified Traffic Signal Technician(s) working on the project and a copy of their IMSA certificate.

 

4.     Shop Drawings/Catalog Cuts:  Submit PDF shop drawings file for traffic signal poles and structures to be furnished on the project. Submit single PDF of catalog cuts files and list manufacturer’s specifications for all items in the contract documents.

 

5.     Fiber Optic Cable: Submit a splicing schematic.

 

C.    Special Requirements:.

 

1.     Comply with the MUTCD.

 

2.     Electrical equipment complying with current NEMA requirements.

 

3.     Ensure materials and work conform to current NEC and IMSA requirements.

 

2525.02     MATERIALS.

Apply Section 4189.

 

2525.03     CONSTRUCTION.

 

A.    Underground.

 

1.     Handhole.

a.     Locations.

1)    Do not construct in ditch bottoms, low areas where ponding of water may occur, or where they will be subject to normal vehicular traffic.

2)    With Engineer approval, additional handholes may be placed, at no additional cost to the Contracting Authority, to facilitate the work.

b.     Excavation:  Excavate as necessary to accommodate the handhole and granular base.

c.     Granular Base:  Install 8 inch thick granular base extending a minimum of 6 inches beyond the outside walls of the handhole.

d.     Placement.

1)    In paved areas, install the handhole at an elevation so the casting is level and flush with the pavement.  In unpaved areas, install the handhole approximately 1 inch above the final grade.

2)    Verify ring placement.  Invert rings when installed in paved areas.

e.     Conduit.

1)    Remove knockouts as necessary to facilitate conduit entrance.

2)    Extend conduit into the handhole, through a knockout, approximately 2 inches beyond the inside wall. Conduit to slope down and away from the handhole.

3)    Place non-shrink grout (complying with Materials I.M. 491.13) in the opening of the knockout area after placement of conduit.

f.      Cable Hooks.

1)    Install cable hooks centered between the knockouts and the top of the handhole.

2)    Place non-shrink grout (complying with Iowa DOT Materials I.M. 491.13) in the opening around the hook after placement of the hook.

g.    Backfill:  Place suitable backfill material according to Section 2552.

h.     Casting:  Place the casting on the handhole. Ensure the final elevation meets the handhole placement requirements.

 

2.     Conduit.

a.     General.

1)    Place conduit to a minimum depth of 30 inches and a maximum depth of 60 inches below the gutterline, unless utility conflicts require deeper placement. When conduit is placed behind the curb, place to a minimum depth of 24 inches and a maximum depth of 48 inches below top of curb.

2)    Change direction at handholes or by bending, such that the conduit will not be damaged or its internal diameter changed. Ensure bends are uniform in curvature and the inside radius of curvature of any bend is no less than six times the internal diameter of the conduit.

3)    On the exposed ends of conduit, place bell-end fittings on PVC or HDPE conduit and bushings on steel conduit prior to installing cable. Extend all conduits a minimum of 2 inches and a maximum of 4 inches above the finished surface of any footing or structural base.

4)    When it is necessary to cut and thread steel conduit, do not allow exposed threads.  Ensure conduits and fittings are free from burrs and rough places. Clean, swab, and ream conduit runs before cables are installed. Use nipples to eliminate cutting and threading where short lengths of conduit are required. Coat damaged galvanized finish on conduit with zinc rich paint. Use only galvanized steel fittings with steel conduit.

5)    Install duct plugs in conduit ends or pack conduit ends with a conduit sealing compound.

6)    Install pull tape in each conduit segment, including empty conduits, and secure to duct plugs at each end.

b.     Trenched Installation.

1)    Place backfill in layers not to exceed 12 inches in depth with each layer thoroughly compacted before the next layer is placed. Ensure backfill material is free of cinders, broken concrete, or other hard or abrasive materials.

2)    Remove all surplus material from the public right-of-way as soon as possible.

c.     Trenchless Installation.

1)    When placing conduit under pavements, use the trenchless installation methods described in Section 2553.

2)    If trenchless methods that compact soils in the bore path are used, provide sufficient cover to prevent heaving of overlying paved surfaces.

3)    Do not allow pits for boring to be closer than 2 feet to the back of curb, unless otherwise specified in the contract documents.

 

3.     Wiring and Cable.

a.     Where practical, follow color codes so that the red insulated conductor connects to the red indication terminal, yellow to yellow, and green to green. Ensure cables are properly labeled at the controller by durable labels, or other appropriate methods, attached to the cables. Label home runs for cables as follows: northwest corner is red, southeast corner is blue, northeast corner is green, and southwest corner is orange.

b.     Install continuous runs of vehicle and pedestrian signal cables from the vehicle or pedestrian signal head to the handhole compartment of the signal pole base. Install continuous runs of vehicle and pedestrian signal cables from the handhole compartment of the signal pole base to the terminal compartment in the controller cabinet. Do not splice signal cables in underground handholes.

c.     Install continuous runs for video detection and emergency vehicle preemption cables from the unit to the controller cabinet.

d.     Install continuous runs of power lead-in cables from the service point to the meter socket and from the meter socket to the controller cabinet.

e.     Install continuous detector cable from each detector loop to the first handhole adjacent to the loop. Ensure cables are properly labeled at the controller by durable labels, or other appropriate methods, attached to the cables. Install continuous homerun cable from the splice made in the first handhole to the terminal compartment in the controller cabinet. Attach the drain wire of the shielded cable to the ground in the controller cabinet.

f.      Provide a minimum of 4 feet of additional cable at each handhole and loosely coil the extra cable on the handhole cable hooks. Provide a minimum of 2 feet of additional cable at each signal pole (measured from the handhole compartment in the pole to the end of the cable). Provide a minimum of 10 feet of additional cable at each controller base. For fiber optic cable, coil the specified length in a wheel shape and hang vertically.

g.     Pull cables through conduit using a cable grip designed to provide a firm hold upon the exterior covering of the cable or cables, and minimize dragging on the ground or pavement.

h.     Install a tracer wire in all conduits with the exception of conduits between detector loops and handholes. Use a silicon-filled wire nut to splice the tracer wire in each handhole and at the controller to form a continuous run.

i.      Fiber Optic Cable and Accessories.

1)    Use a suitable cable feeder guide between the cable reel and the face of the conduit to protect the cable and guide the cable directly into the conduit off the reel. During the installation, carefully inspect cable jacket for defects. If defects are found, notify the Engineer prior to any additional cable being installed. Take care when pulling the cable to ensure the cable does not become kinked, crushed, twisted, snapped, etc.

2)    Attach a pulling eye to the cable and use to pull the cable through the conduit. Use a pulling swivel to preclude twisting of the cable. Lubricate cable prior to entering the conduit with a lubricant recommended by the manufacturer. Use dynamometer or break away pulling swing to ensure the pulling tension does not exceed the specified force of 600 pounds or the cable manufacturer's recommendations, whichever is less. Do not allow the cable to twist, stretch, become crushed, or forced around sharp turns that exceed the bend radius or scar or damage the jacket.  Manually assist the pulling of the cable at each pull point.

3)    Do not pull cable through any intermediate junction box, handhole, pull box, pole base, or any other opening in the conduit unless specified in the contract documents.  Install cable by pulling from handhole or controller cabinet to the immediate next downstream handhole or cabinet. Carefully store the remaining length of cable to be installed in the next conduit run(s) in a manner that is not hazardous to pedestrian or vehicular traffic, yet ensures that no damage to the cable occurs. Storage methods are subject to Engineer approval.

4)    At each handhole, visibly mark or tag cable, “CITY (or COUNTY) FIBER OPTIC”

5)    Secure cables inside controller cabinet so that no load is applied to exposed fiber strands.

6)    Ensure the radius of the bend for static storage is no less than ten times the outside diameter of the cable, or as recommended by the manufacturer. Ensure the radius of the bend during installation is no less than 15 times the outside diameter of the cable, or as recommended by the manufacturer.

7)    Provide cable slack in each handhole, junction box, and cabinet as specified in the contract documents. Where handholes or junction boxes lack sufficient area for cable storage or bend radius requirements, provide equivalent additional slack in adjacent facilities. Coil and bind slack cable at three points around the cable perimeter and support in its static storage position.

8)    Install fiber optic accessories according to the manufacturer’s recommendations and as specified in the contract documents.

j.      Fiber Optic Cable Field Testing:  Provide for each fiber strand both on-reel testing prior to installation and final testing after installation using a high-resolution optical time domain reflectometer (OTDR). Conduct measurements for single-mode fibers at 1310 nanometer and 1550 nanometer wavelengths. Conduct measurements for multimode fibers at 850 nanometer wavelength. Record the identification, location, length, and attenuation measurements of each fiber, and furnish test reports to the Engineer. Replace any cable that fails testing, at no additional cost to the Contracting Authority.

1)    On-reel Testing:  Perform testing for attenuation and continuity using OTDR and a pigtail splice. Complete testing in one direction only. Acceptable test results will be within ± 3% of factory-supplied attenuation measurements. Except for access to and test preparation of one end of the newly furnished cable, preserve the cable in its originally-shipped condition. Furnish test reports to the Engineer prior to installation.

2)    Post installation, test 100% of the new cables’ fiber count bi-directionally with an OTDR at 1310 nm and 1550 nm; in addition, use an optical loss test set (OLTS) to test all fibers at both wavelengths. Also test existing fibers that are spliced to or re-spliced as part of this contract in both directions and at both wavelengths. Provide the Engineer with up to five copies of any software required for viewing electronic files of the OLTS and OTDR traces. Use test equipment equal to EXFO FTB-500 OTDR meter, and Fluke DTX-CLT OLTS meter.

3)    Ensure all test equipment has been factory certified within the last year. Provide copies of the certification 10 days prior to testing.

4)    Record test results through the meter manufacturer’s software with data compiled in a PDF. Additional alteration using software beyond the meter manufacturer’s software will not be allowed. Submit test results in a format approved by the Engineer. Provide completed test forms on each fiber to the Engineer. Also provide native test (electronic version) with no alterations and meter software for viewing of fiber traces. At a minimum, ensure test results show the following:

·         Cable and fiber identification (as approved by the Engineer)

·         Operator name

·         Date and time

·         Setup and test parameters including wavelength, pulse width, range, scale, and ambient temperature.

·         Test results for OTDR test in both directions for total fiber trace, splice loss/gain (dB), connector loss (dB), all events greater than 0.05 dB, measured length from cable markings, and total length from OTDR.

·         Test results for attenuation test including measured cable length (cable marking), total length (from OTDR test), number of splices (from as-built) and total link endto-end attenuation in each direction, and the bidirectional average.

5)    Ensure OTDR testing uses launch and receiving cables minimum 3300 feet or greater than the dead zone for the OTDR used for this test.

6)    Ensure all fiber connectors are cleaned and checked for dirt, scratches, or chips before installed in adapters and testing. Install all dust covers after testing is complete.

·         Ensure the fiber optic cable has a maximum attenuation of 0.4 dB/km at 1310 nm and 0.3 dB/km at 1550 nm when measured with an OLTS.

·         Ensure each connector has an averaged loss value of 0.25 dB or less when measured bi-directionally with an OTDR at 1310 nm and 1550 nm.

·         Ensure each splice has an averaged loss value of 0.08 dB or less when measured bi-directionally with an OTDR at 1310 nm and 1550 nm.

 

4.     Footings and Foundations.

a.     Excavation:  Excavate to the size, shape, and depth specified in the contract documents. Ensure the bottom of all foundations rest securely on firm undisturbed soil.  Minimize over-excavation to ensure support and stability of the foundation. Notify the Engineer immediately if high water and/or poor soils are encountered during excavation. Provide circular forms if needed at no additional cost to the Contracting Authority.

b.     Foundation:  Provide a means for holding all of the following elements rigidly in place while the concrete is being placed.

1)    Forms.

a)    Set the forms level or sloped to meet the adjacent paved areas.

b)    When adjacent to paved areas, shape the top 11 inches of the footing to be square and flush with the surrounding paved area. Provide preformed expansion material between the footing and paved areas.

c)    When installed in an unpaved area, set the top of the footing 2 inches above the surface of the ground.

2)    Reinforcing Steel:  Install reinforcing steel.

3)    Conduit:  Install conduit.

4)    Anchor Bolts.

a)    Set anchor bolts using a template constructed to accommodate the specified elevation, orientation, and spacing according to the pole and controller manufacturer's requirements.

b)    Center the pole anchor bolts within the concrete footing.

c)    Protect the anchor bolts until poles are erected.

d)    Orient controller footing with the back of the cabinet toward the intersection such that the signal heads can be viewed while facing the controller, unless otherwise directed by the Engineer.

5)    Concrete.

a)    Place concrete to form a monolithic foundation. Consolidate concrete by vibration methods.

b)    Finish the top of the base level and round the top edges with an edging tool having a radius of 1/2 inch. Provide a rubbed surface finish on the exposed surface of the footing.

c)    Allow the footings to cure a minimum of 4 days prior to erecting the poles and 7 days prior to installing the mast arms. Times may be shortened if supported by strength test results.

c.     Backfill:  Place suitable backfill material according to Section 2552.

 

5.     Bonding and Grounding.

a.     Ensure the traffic signal installation is grounded as required by the National Electric Safety Code.

b.     Install a ground rod at each signal pole and controller footing.

c.     Use PVC conduit within the footing to accommodate the connection between the top of the footing and the ground rod.

d.     Bond poles to ground rods with copper wire. Connect ground wires to ground rods with approved mechanical connectors.

e.     Bond rigid steel conduit ends in handholes with copper wire and approved fittings.

 

B.    Detection.

 

1.     Detector Loop Cable Installation.

a.     Coordinate the location of the detector loop with the Engineer. Obtain the Engineer’s approval prior to cutting the pavement.

b.     Saw to ensure proper depth and alignment of the slot.  Make a 2 inch deep clean, straight, well-defined 3/8 inch wide saw cut without damage to adjacent areas. Overlap the saw cuts where the detector loop changes direction to provide full depth at all corners. Do not use right angle or corners less than 90 degrees. Minimize crossing the number of pavement joints where possible. Route the sawcut from the loop to the edge of pavement perpendicular to the flow of traffic, maintaining at least 1 foot of clearance from parallel joints.

c.     Before installing the detector loop cable, check the saw cuts for the presence of jagged edges or protrusions and remove if present. Clean and dry the saw cuts to remove cutting dust, grit, oil, moisture, or other contaminants. Clean by flushing with a stream of water under pressure. Use oil-free compressed air to dry the saw cuts.

d.     Install detector loop cable without damage. Place three turns of the detector loop cable into the saw cut. Seal the ends of the tubing at the time of placement to prevent entrance of moisture.

e.     Ensure the detector loop cables are in the bottom of the saw cut. Place detector loop sealant within the saw cut area. Comply with the manufacturer’s instructions for mixing and using the detector loop sealant.

f.      Install preformed loop detector according to the manufacturer’s recommendations.

g.     Identify each detector loop cable in the handhole by phase and location. Wind loops that are physically adjacent in an individual lane or adjacent lanes with opposite rotation (i.e. No. 1 clockwise, No. 2 counter-clockwise, No. 3 clockwise, etc.). Rotation reversal can be accomplished by reversing leads at the handhole.

h.     Twist, with at least five turns per foot, all lengths of loop wires and tubing that are not embedded in the pavement.

i.      Identify all detector loop lead-in cables with appropriate detector numbers.

j.      Use a detector loop cable splice kit for the electrical splice between the detector loop cable and the detector loop lead-in cable to the controller.

1)    Ensure splice kit provides a watertight protective covering for the spliced wire, the shielding on the detector loop lead-in cable, and the end of the tubing containing the detector loop cable.

2)    Use a manufactured electrical splice kit approved by the Engineer.

k.     Test all loops and document by using the following procedures:

1)    Determine the insulation resistance of the loop wire using a "megger" with 500V applied to either loop wire to earth ground.  The resistance is to be greater than 100 megohms.

2)    Determine the inductance of the loop using a loop inductance meter.

 

2.     Pedestrian Push Button Detectors.

a.     Install according to the manufacturer’s recommendations.

b.     Seal the wire entrance into the pedestrian push button assembly.

 

3.     Video Detection Camera System:  Install according to the manufacturer’s recommendations and as specified in the contract documents.

 

4.     Wireless Magnetic Sensors (Pod/Puck): Install according to the manufacturer’s recommendations.

 

C.    Communications.

 

1.     Traffic Monitoring System:  Install according to the manufacturer’s recommendations and as specified in the contract documents, as well as the following:

a.     Position camera dome on the pole as directed by the Engineer.

b.     Test installed system under the supervision of the Engineer, and certify as fully-functional.

 

2.     Fiber Optic Hub Cabinet:  Install according to the manufacturer’s recommendations and as specified in the contract documents.

 

D.    Cabinet and Controller.

 

1.     Cabinet.

a.     Install according to the manufacturer’s recommendations and as specified in the contract documents.

b.     Install on pre-placed caulking material on the concrete base. After the cabinet is installed in place, place caulking material around the base of the cabinet.

 

2.     Controller and Auxiliary Equipment:  Install according to the manufacturer’s recommendations and as specified in the contract documents.

 

3.     UPS Battery Backup System:  Install according to the manufacturer’s recommendations and as specified in the contract documents. Provide service outlet that is not connected to the battery backup system.

 

4.     Emergency Vehicle Preemption System:  Install according to the manufacturer’s recommendations and as specified in the contract documents.

 

E.    Poles, Heads, and Signs.

 

1.     Vehicle and Pedestrian Traffic Signal Heads.

a.     Inspect each signal head assembly while still on the ground for the following:

·         Physical defects

·         Visor type

·         LED wattage

·         Lens orientation

·         Wiring connections

b.     Attach signal head mounting hardware according to the manufacturer’s recommendations. Apply anti-seize compound to all mechanical fasteners.

c.     Adjust each signal head both vertically and horizontally to approximate a uniform grade of all like signal heads.

d.     During the course of construction and until the signals are placed in operation, cover signal faces or turn away from approaching traffic. Plumb and aim the heads. Confirm placement of signal heads with the Engineer.

 

2.     Traffic Signal and Pedestal Poles.

a.     Erect all poles vertically under normal load.

b.     Securely bolt the bases to the cast-in-place concrete foundations using the procedures in Articles 2522.03, H, 2, a through h.

c.   Use a torque wrench to verify that a torque at least equal to the computed verification torque, Tv, is required to additionally tighten the top nuts. An inability to achieve this torque shall be interpreted to indicate the threads have stripped and shall be reported to the Engineer.

 

Tv = 0.12dbFI

Where:

Tv = verification torque (inch-kips)
db = nominal body diameter of the anchor rod (inches)
FI = installation pretension (kips) equal to 50% of the specified minimum tensile strength of ASTM F 1554, Grade 36 rods, and 60% for the rest of threaded fasteners.

 

d.     After leveling the poles, use non-shrink grout or a rodent guard between the pole base and the foundation. When non-shrink grout is used, neatly finish exposed edges of grout to present a pleasing appearance, and place a weep hole in the grout.

e.     Apply anti-seize compound to all mechanical fasteners on pole access doors.

f.      Install pedestrian push button post caps with tamper-proof set screws per manufacturer’s direction or by driving the cap a minimum of 1/2 inch onto the post.

 

3.     Traffic Signs:  Install signs using universally adjustable sign brackets banded to the pole. Apply anti-seize compound to all mechanical fasteners.

 

F.     Temporary Traffic Signal.

Construct according to Article 2528.03, H and to the configuration specified in the contract documents.

 

G.    Surface Restoration.

 

1.     Replace or reconstruct features removed as a part of the work, such as sidewalks, driveways, curbs, roadway pavement, unpaved areas, or any other items.

 

2.     Complete restoration according the applicable sections of the Standard Specifications.

 

H.    Signal Turn On.

Six days in advance of the scheduled signal turn on, place static signs or portable dynamic message signs (PDMS) on at least each of the major street approaches indicating day of week when the traffic signals will be active. If required, special Traffic Signal Ahead signs or PDMS with “Signal Active” message may be left in place for up to 7 days following activation.

 

I.      Testing.

 

1.     Notify the Engineer 2 working days in advance of the time and date the signal or signal system will be ready for turn on. Do not turn on the signal or signal system without authorization of the Engineer.

 

2.     Ensure a representative from the manufacturer and/or supplier of signal controller or other authorized person is at the project site when the signal controllers are ready to be turned on to provide technical assistance including, as a minimum, programming of all necessary input data.

 

3.     All required signal timing data will be provided by the Engineer.

 

4.     A test period of 30 calendar days will start upon confirmation from the Engineer that the signal or signal system is operating consistent with the project requirements. Any failure or malfunction of the equipment furnished by the Contractor, occurring during the test period will be corrected by the Contractor at no additional cost to the Contracting Authority. Upon confirmation by the Engineer that any failure or malfunction has been corrected, a new test period of 30 calendar days will start, exclusive of minor malfunctions such as lamp burnouts. Repeat this procedure until the signal equipment has operated satisfactorily for 30 consecutive calendar days.

 

5.     After signal turn on and prior to completion of the 30 calendar day test period, respond, within 24 hours, to perform maintenance or repair of any failure or malfunction reported.

 

J.     Documentation.

 

1.     Provide file documentation packages with each signal system, consisting of the following:

a.     Complete cabinet wiring diagram.

b.     Complete physical description of the equipment.

c.     Controller printout or equal documentation of initial controller settings installed in the field or in the office.

d.     Product manuals for all cabinet equipment.

e.     Standard industry warranties on equipment supplied.

f.      Documentation of field cable labeling scheme.

g.     Diagram of phasing and detector locations.

h.     One set of as-built construction plans indicating changes from the original contract documents.

 

2.     Supply two complete sets of documentation. One set to be placed in the controller cabinet and the other set (less construction plan) to be delivered to the Engineer. Electronic (PDF) submittal of the documentation is acceptable, if allowed by the Engineer. 

 

 

K.    Traffic Signal Removal.

 

1.     Remove and salvage traffic signal and pedestrian poles and posts, including mast arms, signal heads, wiring, mounting hardware, and associated equipment.

 

2.     Remove and salvage controller cabinet and controller, including associated equipment.

 

3.     Remove and dispose of handholes and abandoned conduit as specified in the contract documents.

 

4.     Remove concrete pads and foundations, including reinforcing steel to a depth of 4 feet below established grade. Furnish, place, and compact backfill according to Section 2552.

 

5.     Restore disturbed surfaces to match adjacent areas.

 

6.     Deliver salvaged materials to the location specified in the contract documents.

 

2525.04 METHOD OF MEASUREMENT.

 

A.    Traffic Signalization.

Lump sum item; no measurement will be made.

 

B.    Removal of Traffic Signalization.

Lump sum item; no measurement will be made.

 

2525.05 BASIS OF PAYMENT.

 

A.    Traffic Signalization.

Payment will be at the lump sum price for Traffic Signalization. Partial payment will be made according to the approved schedule of unit prices for those materials installed.

 

B.    Removal of Traffic Signalization.

Payment will be at the lump sum price for Removal of Traffic Signalization. Lump sum price includes: removal of poles, concrete pads, foundations, wiring, traffic signal cabinet and equipment, pedestrian signal equipment, and handholes; delivery of removed materials to the location specified in the contract documents (if specified); furnishing, placing, and compacting backfill in all excavations; and restoring disturbed surfaces.