915 The presence detection mode shall provide a vehicle presence output signal for as long as a vehicle is stopped in the roadway sensor zone or as otherwise specified. The detectors shall be designed "fail safe." In case of power failure, the output relay shall remain in the closed position. All detector units shall be designed to operate from a 120 volt (plus or minus 10 percent (10%) ), 60 Hz, AC power line service. The detector units shall be completely self -contained and shall include an integral, fused power supply. The detector chassis shall be enclosed in a removable, sturdy aluminum or other non-corrosive metal case. The case shall furnish the chassis protection from moisture and other ambient conditions. The detector shall be of such a size as to readily fit into a cabinet with the signal controller when so required. All electrical connect ions to and from the detector unit shall be made through a multiterminal, quick disconnect, plug -type connector and wiring harness. Each wiring harness shall be at least thirty -six (36) inches long. The harness end opposite the connector shall have color -coded leads or labeled sleeves. The harness connection shall be such that the detector may be replaced with a similar unit, without the necessity of disconnecting and reconnecting individual wires leading therefrom. If the detector is mounted in the same cabinet with signal control equipment, all harness connections except power supply and vehicle call to controller shall be made on a separate terminal strip mounted in the controller cabinet for that purpose. Power supply connection and a vehicle call to controller may be connected to terminals on the controller back -panel. A front panel light, clearly visible under full daylight conditions, shall be provided to indicate when a vehicle is in the detection area. An instruction manual and an internal wiri ng schematic drawing shall be provided with each detector to facilitate installation, operation and service of the units. The Contractor or equipment supplier shall turn over to the Division any guarantee or warranties which are given by the equipment man ufacturer as a normal policy. NOTE: The above general design requirements do not apply to audible pedestrian detectors. Audible pedestrian push buttons are covered in 715.42.5.4.
715.42.5 2-Loop Traffic Detectors (LPS): The purpose of this section is to set forth
functional specifications and design requirements for a solid state digital, automatically tuned and completely self -contained, shelf -mounted unit for detecting the passage or presence of vehicles when connected to a wire loop embedded in the roadway surface. The general design requirements in 7l5.42.5.l and NEMA standards shall apply except when the specific requirements exceed those in 7l5.42.5.l and NEMA. The detector shall respond only to vehicles either stopped in or passing over any po rtion of the roadway loop. The unit shall be capable of driving loops of various sizes and configurations within a range of 30 -1,000 microhenries. It shall be capable of tuning loops of up to 50 feet in length with up to 1,000 feet of lead -in wire. The detector shall be capable of detecting vehicles traveling at any speed between zero and 100 mph. Individual sensor -detector assemblies shall operate satisfactorily under conditions where adjacent sensors are located within 6 feet of each other. The follo wing minimum controls or equivalent shall be provided on the front panel of the detector.
i.Frequency ................................ .................... High, median and low ii. Sensitivity ................................ ........................ As specified below iii. Presence ................................ ........................... As specified below Sensitivity -Three selections of minimum thresholds that will detect changes in total loop inductance as low as (l) 0.02%, (2) 0.08% and (3) 0.32%. Presence -Three selections of presence time modes (1) long -3.5 minutes (minimum),
2.medium -20 seconds (minimum), (3) pulse – 125 25 milliseconds pulse per vehicle. All electrical connections to the detector shall be made through a single front -mounted, 11 pin, amphenol connector. The connection mounted on the detector shall be male -type and shall be protected and rigidly fixed. A mating female r eceptacle with appropriate cable clamps and at least 4 feet of connecting harness cable shall be provided with each detector. The other end of the cable shall have color -coded leads, or labeled sleeves, each of which shall be fitted with positive grip, an d crimp spade terminals for field connections. The 11 pin connector on the detector shall have the following pin assignments: (Adapter harnesses will not be acceptable.) Pin Number Circuit 1 Fused side of 120 volt AC line 2 Neutral side of 120 volt AC line 3 Not Used 4 Earth 5 Relay common contact 6 Relay, normally open, contact 7 Loop 8 Loop 9 Relay, normally closed, contact 10 Not Used 11 Not Used Detector loopwire and detector feeder cable shall be as specified in 715.42.13. Loop layout and configuration shall be specified in the plans, or as directed by the Engineer. Output interfacing shall be by means of relay circuitry. All components shall meet the latest re quirements of the NEMA Standards. Type LPS SD detectors shall meet all the requirements of the specifications for
715.42.5 2 -Loop Traffic Detectors (LPS), but in addition, must have separate built -in
stretch and delay timers with 0 to 15, 0 to 30, and 0 t o 60 seconds timing ranges.
715.42.5 3: Blank
715.42.5 4 -Audible Pedestrian Push Buttons: A solid -state digital, pole -mounted,
pedestrian push button detector and appurtenances with audible and vibratory features to assist disabled users who have hear ing and/or sight impairments. Appurtenances are to include the associated signal power interface or control board assembly to be mounted in the corresponding pedestrian signal head with the associated cabling. The push button detector is to be MUTCD 2009 , NEMA TS2 and ADA compliant, made of sturdy construction consisting of a base housing with a removeable cover, a pushbutton with normally open contacts and include all electrical and mechanical parts required for operation. The detector shall include an adjustable automatic gain control with 917 the associated microphone to keep audio output from 0 to 5 dB above ambient conditions. The push button detector and its associated contacts and housing are to be resistant to mechanical shocks and abuse. The unit shall be able to withstand a concentrated force of 50 pounds applied to the button or any exposed portion without damage. Furnish a housing with geometry and/or hardware suitable for mounting on poles of various diameters. The removeable cover assembly i s to be fastened to the base housing with stainless steel machine screws resulting in a weatherproof and shockproof assembly. The maximum force required to operate the pushbutton is 5 pounds. Furnish a raised or flush pushbutton with a minimum of two ( 2) inches at its smallest dimension. Furnish pedestrian pushbutton signs that are a minimum thickness of 0.07 -inch for steel or 0.10 -inch for aluminum with baked enamel paint for steel signs and baked enamel paint or non -reflective sheeting for aluminum signs.
715.42.6 Adjustable Face Signal Heads:
715.42.6 1-Definition of Terms:
Lane Control Signal Head: An assembly containing one or more signal faces having indications used to permit or prohibit the use of specific lanes of a street or highway. Lens: That part of the optical unit which redirects the light coming directly from the lamp and its reflector. Optically Programmed Signal Head: An assembly containing one or more signal faces which may be designated accordingly as one -way, two -way, etc., permitting the visibility zone of the indication to be determined optically. Optical Unit: An assembly of redirecting cover glass or lens, reflector, lamp and lamp socket with the necessity supporting parts to be used for providing a single signal indication. Pedestrian Control Signal: A traffic control signal, manually, electrically or mechanically operated which is e rected for the exclusive purpose of directing pedestrian traffic at signalized locations. Signal Face: That part of a signal head provided for controlling traffic in a single direction. Turning indications may be included in a signal head. Signal Head: An assembly containing one or more signal faces which may be designated accordingly as one -way, two -way etc. Signal Indication: The illumination of a traffic signal lens or equivalent device or a combination of several lenses or equivalent devices at t he same time. Traffic Control Signal: Any device, whether manually, electrically or mechanically operated, by which traffic is alternately directed to stop and permitted to proceed. NOTE -The above list of definitions may not be complete for all terms used. Final interpretations of all terms is the responsibility of the Engineer (see Section 101 of Specifications).
715.42.6 2-Traffic Control Signal Heads: Each signal shall be of the adj ustable,
colored light, vertical type with the number and type of sections described and shown on the Plans. Each head shall have an indication in one direction only and shall be adjustable through 360 degrees about a vertical axis. All new signal heads at any one intersection shall be of the same make and type. Position of Signal Indications: All signal indications shall be in a straight line and shall be in the following order although all indications shown need not be included in all cases. In vertical signals, Position 1 shall be at the top, the Position 8 at the bottom. In horizontal signals, Position 1 shall be at the left (facing the signal), and position 6 at the right. Position Signal Indication Vertical Horizontal 1 1 Red 2 2 Yellow 3 4 Green 4 5 Straight Thru Arrow 5 3 Left Turn Arrow 6 6 Right Turn Arrow 7 Don't Walk Symbol 8 Walk Symbol Pedestrian signal indication shall be mounted separately below the conventional post mounted signal to allow for separate directional facing for these indications and to obtain definition of the signal by spacing. At no time will a pedestrian signal indication be allowed to hang below an overhead -mounted signal. Assembly: Each head shall consist of an assembly of individual interchangeable sections securely bolted together to form a unit. There shall be no tie rods used in the assembly. The finished assembly shall present a clean, neat appearance. Each individual section shall house a complete optical unit. It shall be possible to assembly any combination of eight
8.inch and twelve ( 12) inch heads without the use of special adapters. The top and bottom of each section shall have an opening to accommodate standard 1½ inch (DN40) pipe brackets. The opening shall be in line vertically. The assembly shall be capable of being rotated between standard waterproof supporting brackets or trunnions and thus aimed in any direction in the horizontal plane. The port ion of each section adjacent to the bracket openings and the portion used for connecting sections shall be properly reinforced to provide sufficient strength to resist shock, vibration and impact damage. Each section shall have lugs for the mounting of at least one six -position, twelve - terminal, barrier -type terminal block. Each section shall have lugs or pads such that backplates may be mounted without drilling or tapping the section. The housing door shall be a one -piece square casting, having two hing e locations on the left side and at least one latch location on the right side. The hinges shall have stainless steel pins at least 3/16 inch in diameter. The latch shall consist of (1) a latch jaw on the door and a stainless steel latch screw, wing nut, and washer securely affixed to the housing, or (2) a captive wing nut, washer, and screw assembly on the door and a captive nut in the housing. It shall be possible to open and remove the door without the use of any tools. The door shall have a gasketed opening that shall provide a visible lens diameter of 7 ¾ to eight ( 8) inches for a nominal eight ( 8) inch lens and 11½ to twelve ( 12) inches for a nominal twelve ( 12) inch lens. All lenses shall be as described in 715.42.6.4. 919 The door shall have four e qually spaced visor attachment points around the lens opening. Visors shall be at least seven ( 7) inches long for an eight ( 8) inch lens and at least 9½ inches long for a twelve ( 12)-inch lens. Visors shall be described as cutaway, tunnel, or full circle . All heads shall be supplied with tunnel visors, unless otherwise noted on the Plans or unless prior permission from the Division has been received. All new replacement signal heads at any one intersection shall have the same type as the existing visors supplied, unless otherwise specified on the Plans. Visors shall be designed with a downward tilt between 3½ degrees and 5 degrees, shall eliminate the escape of light from one indication to another, and with the optical unit, shall eliminate the return o f outside rays entering the unit from above the horizontal (known as sun phantom). The Signal Sections, all brackets, trunions and suspension devices shall be painted in accordance with ITE ( Institute Transportation Engineers ) Specifications. The inside of the signal section visors shall be flat black enamel to eliminate objectionable reflections. Non - Metallic signal sections must have a color impregnated finish and be the same color as the enameled sections. The inside of non -metallic visors must also be painted with a permanent flat black enamel or use other means to prevent reflections. The optical unit shall consist of the lamp, lampholder, reflector, lens gasket and lens, and shall be so designed that all light emitted by the unit passes through th e leans and so that any possibility of false indications is eliminated. The lampholder shall be of heat resisting material designed to properly position a medium screw base traffic signal lamp, with means to accommodate a lamp having light center 2 -7/16 i nches in length for the 60 -watt and 100 -watt series and three ( 3) inches in length for the 150 -watt series. The lampholder shall be provided with a lamp grip to prevent the lamp from working loose due to vibration. Provision shall be made on either the lampholder or the reflector holder to permit rotation of the lamp so that the lead -in wires are up and the lamp shall be retained securely in that position, but no change in position of the socket with respect to the optical center of the reflector shall oc cur. The metal portion of the lampholder shall be compatible with brass or copper. Each lampholder shall be provided with two coded No. 18 or larger lead wires, type TEW, 600 -watt, AWM fixture with 2/64 in ch, 221ºF rating thermoplastic insulation, secure ly fastened to the socket, and with sufficient length to reach the terminal block with the holder or door fully open. The thermoplastic insulation shall at minus 30 F be capable of being bent six times around a one ( 1) inch mandrel without damage to its insulating properties at rated voltage. A suitable terminal block or blocks shall be provided in the second section from the top or in each section of one -section heads. The terminal block shall have at least one section fo r each signal head section plus at least two additional sections per block. Terminal blocks shall be standard commercially available units. Reflectors shall be specular aluminum in accordance with the latest ITE Specifications and shall be mounted in a r eflector holder. The reflector holder shall provide a rigid reflector mounting to assure proper alignment between the lens and the reflector with the door closed. The reflector shall have a lampholder opening in the back. The reflector shall have a bead or flange on the outer edge to stiffen the reflector and insure its dimensional stability. The reflecting surface shall be totally free from flaws, scratches, defacements and mechanical distortion.
Source: West Virginia Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 937–941 of 1,006.