894 TMA’s shall be designed to be attached directly to and cantilevered off the rear of the host vehicle. TTMA’s shall incorporate an axle and shall be designed to be towed behind the host vehicle. The manufacturer shall make adequate requirements and recommendations available for necessary modifications to be made to host vehicles to adequately support the device. The manufacturer shall also make available recommended buffer distances for the device s based on expected post impact roll -ahead distances taking into consideration a variety and range of factors such as host vehicle weight, host vehicle speed, impacting vehicle speed, vertical grade, etc. TMA’s and TTMA’s shall be equipped with all nece ssary safety features required for legal highway use such as brake lights, taillights, turn signals and ICC bar lights. The front of the device shall be adequately delineated to provide high conspicuity for approaching traffic.
715.41.5 Product Submis sion and Approval: Impact Attenuator devices described in
Sections 715.41.1 through 715.41.4 to be considered for inclusion on the Division’s Impact Attenuator - MASH APL shall be submitted to the Materials Division following the current procedures specif ied in MP 106.00.02. The manufacturer should include all relevant documentation and information, including but not limited to product data sheets and bulletins, product specifications and recommendations, product manuals, engineering drawings, and any ot her requested information. Devices shall be demonstrable to be crashworthy by means specified in official guidance issued by the WVDOH.
715.42 Traffic Signal Materials and Equipment :
715.42.1 Pre-timed Fixed Cycle Traffic Signal Controllers:
715.42.1 1-Definition of Terms: Following are definitions of terms used by the
Division for pre -timed fixed cycle traffic signal controllers: Audible Pedestrian Detector: A detector, usually of the push button type installed near the roadway, capable of being operated by hand, and having audible and vibratory features for both the purposes of location of the device and notification of the operations of the device. Automa tic Reset: A reset by means of which the offset or beginning of the green is checked automatically and adjusted, if necessary, once each time cycle. Cabinet: A dustproof and weatherproof enclosure for housing the controller and associated equipment. Circuit Contact Cam Shaft: A device to operate the circuit contacts to provide the desired interval sequence. Controller: A complete electrical mechanism for controlling the operation of traffic control signals, including the timer and all necessary auxil iary apparatus mounted in a cabinet. Double Automatic Reset: A reset by means of which it is possible to automatically select any one of two automatic resets. Emergency Feature: A mercury contact bus bar relay installed in a controller, which when ener gized from a manual switch, remote point, discontinues the normal signal 895 operation and displays special signal indications for the movement of high speed fire apparatus, etc. Field Terminals: Devices mounted on a panel board for connecting all wires ente ring the controller cabinet. Flashing Feature: A mercury contact bus bar relay installed in a controller which, when energized from a manual switch, remote point or by automatic time switch, discontinues normal signal operation and causes the flashing of any predetermined combination of signal lights. Interval: The part or parts of the signal cycle during which signal indications do not change. Interval Sequence: The order of appearance of signal indications during successive intervals of a cycle. Jack Mounted Relay: A relay which may be removed or replaced without the use of tools and without disturbing any wiring. Local Controller: A controller for operating traffic control signals at an intersection which may be isolated or included in an interc onnected traffic control signal system. Manual Operation: The operation of a controller assembly by means of a hand - operated device(s); (i.e., push -button). Manual Reset: A reset by means of which it is possible to manually adjust the offset or beginni ng of the green. Master Controller: An automatic device for supervising a system of controllers, maintaining definite time inter -relationship, selecting among alternate available modes of operation or accomplishing other supervisory functions. Offset: The number of seconds or percent of the cycle length that a defined time - reference point (normally the start of major street green) at a traffic signal occurs after the time-reference point of a master controller or of an adjacent traffic signal. Offset C ontrol Switch: A device which when operated stops the timing of the cycle length and intervals in order to manually adjust the offset. Offset Dial: A calibrated dial on an automatic timer equipped with adjusting devices by means of which it is possible to set any desired offset of the beginning of the green traffic control signal indication. Offset Interrupter: A device which will distribute over two or more cycles the time required for large offset changes. Pedestrian Phase (Pedestrian Movement): A traffic phase or traffic movement allocated exclusively to pedestrian traffic. Panel: A panel board within the controller cabinet upon which are mounted fuse receptacles, circuit breakers, contactors, terminals, relays, and electrically operated switches and other equipment, all suitable insulated. Pre-timed Controller: A controller for the operation of traffic signals with predetermined:
i.Fixed cycle length(s). ii. Fixed interval duration(s) iii. Interval sequence(s) Radio Interference Suppressor: A device inserted in the power line in the controller assembly (cabinet) than minimizes the radio interference transmitted back into the power supply line, which interference may be generated by the controller or other mech anisms in the cabinet. 896 Relay Jack: A set of clips, plugs or receptacles in a controller or cabinet by means of which a relay may be mounted or connected to the circuit. Reset: An adjustment mechanism applied to an automatic controller providing for the setting up of the timing arrangement of the start of the green traffic control signal indication. Reset Interrupter: A device which will automatically distribute the time lag resulting from a particular resetting over a period of time varying from one t o several cycle lengths. Shutdown Feature: A mercury contact bus bar relay installed in a controller which, when energized from a manual switch, remote point or by an automatic time switch, discontinues normal traffic control signal operation and turns t he signal indications off. Shutdown Switch: A switch in a controller which may be operated by hand to discontinue the operation of traffic control signals. Signal Circuit Contact: A device arranged to energize or de -energize signal light circuits durin g a specified interval. Signal Indication: The illumination of a traffic signal lens, or equivalent device, or of a combination of several lenses or equivalent devices at the same time. Split: A division of the cycle length allocated to each of the vari ous phases (normally expressed in percent). Synchronous Controller: An automatic controller operated by a synchronous motor which will keep in step with the frequency of the power supply circuit. Triple Automatic Reset: A reset by means of which it is possible to automatically select any one of three automatic resets. Time Cycle: The number of seconds required for one complete revolution of the timing dial or complete sequence of signal indications. Time Cycle Indicator: An indicating device applied to an automatic timer for indicating the time cycle in seconds. Timer: An automatic timing unit in a controller, including all dials, dial transfer relays, switching and circuit contacts, motors, gears, camshaft, etc. Time Switch: A device for the auto matic selection of modes of operation of traffic signals in a manner prescribed by a predetermined time schedule. Timing Dial: A calibrated dial on an automatic timer equipped with adjusting devices by means of which it is possible to divide the time cyc le into the required number of intervals and set up the offset and interlock. Traffic Phase: Those right -of-way and clearance intervals in a cycle assigned to any independent movement(s) of traffic. Yellow -Red Flash Terminals: Addition terminals installed in a traffic signal controller so wired that by an interchange of jumpers, flashing operation may be arranged to give either yellow or red on the main or cross streets.
715.42.1 2-General Design Requirements: The following are minimum design and
operating requirements for all pre -timed, fixed cycle traffic signal controllers and associated equipment described in these specifications. The signal time cycle shall be constant and accurate, regulated by the power line frequency. Neither cycle length variations nor interval timing variations shall occur if voltage of the power line varies between the limits of 10 percent (10%) above and 10 percent (10%) below 120 volts, 60 Hz AC sta ndard service voltage. Similarly, neither cycle length variations nor interval timing variations shall occur if outside cabinet 897 temperatures change to any value between -30F and plus 122 F. Maximum inside cabinet temperature for above operation is plus 165F. It shall be possible to accurately set or adjust the cycle lengths between the limits of 30 and 130 seconds with accurate and definite settings within this range in five -second steps up to 100 seconds, and in ten -second steps above 100 seconds. Thi s adjustment shall be accomplished by a change of marked gears requiring no more than the use of simple tools. Gear and gear shaft shall be designed to prevent slippage. Gear meshing pressure must be adjustable. The cycle length in operation shall autom atically be indicated on a scale visible on the front of the dial unit. All pre -timed controllers shall contain three timing dials and be capable of being interconnected into a three -dial, three -offset system and shall include all the necessary keys, cont acts, rider arms, etc. The signal color sequence period adjustments and offset adjustments shall be made on the same timing dial without the aid of any tools. The timing dial shall be calibrated for the signal color period in steps of one percent (1%) from 1 to 99 percent (1-90%) . The offset calibration shall be in reverse order of the signal color sequence period. Each offset key shall be clearly identifiable as to its function and distinguishable from the color period keys. All keys for a given functi on shall be identical and each key having a specialized function shall be appropriately colored or otherwise identifiable to provide a visual indication of such function. Any changes in operation of traffic control signal lights caused by turning the sign al lights off, or turning them on flashing operation, shall not interfere with the continued in - time operation of the timer motor presently operating in each controller. A transfer from such special operation back to normal automatic operation shall immedi ately establish the normal time cycle and subsequently the in -time relation. The dial transfer mechanism shall be so designed that not more than one dial may operate at any one time. Dial No. 1 shall operate in absence of call for dial No. 2 or dial No. 3 or when there is a conflict on dial calls. Each controller shall be furnished with three service manuals complete with all necessary instructions and diagrams for the installation and maintenance of the equipment supplied. Each controller shall be supp lied with three complete sets of wiring diagrams. These wiring diagrams shall identify the color code or wire tagging used in all connections.
715.42.1 2.1-Interval Sequence: The controller shall provide consecutive divisions
of the time cycle termed " intervals," during which time the combination of signal indications do not change. Each controller shall be provided with 12 or 16 interval cams. The cams shall be programmed so that a minimum number of dial unit keys are required for the plan specified phasing. If phasing is not specified, the cam lobes are not to be broken out.
715.42.1 2.2-Interval Adjustment: The controller shall provide for the setting of each
interval of the cycle by means of a positive setting on each calibrated dial. The setti ng shall at all times show a visual indication of the amount of time allocated to each interval, in units of percent of the cycle length. When the controller is operating within a specified voltage and temperature limits, the time duration of each interva l shall be within plus or minus 500 milliseconds of the time indicated by the setting of that interval, and timing of 898 successive intervals shall be without cumulative errors that would affect the accuracy of the cycle length. Each dial unit shall be provi ded with a scale calibrated in steps of one percent (1%) of the cycle length or one second, and shall provide for the accurate setting of any interval within the range of adjustment from 2 percent (2%) to 90 percent (90%) of the cycle length or from one se cond to 99 seconds. The minimum time for any interval is not required to be less than one second whenever that is greater than two percent (2%) of the cycle length, nor is the minimum time for any interval required to be less than two percent (2%) of the cycle length when that is greater than one second. The timing controls shall be on the front of the controller unit, easily identifiable, and it shall not be necessary to remove or change wires or contacts or to use any tools in making interval adjustment s. The three controller dial units specified shall provide for separate programs of interval timing. The dial units shall be readily identifiable and a change of one dial shall not affect or alter the other two dials. Dial transfer shall be accomplished at the beginning of main - street green. The cam -shaft dial synchronization key (commonly called the camswitch release key, interlock, drum release or release key) shall terminate the main -street green interval. No more than two cycle lengths shall be req uired to effect a dial transfer.
715.42.1 2.3-Mechanism: The controller components shall be of unitized design and
readily interchangeable. All mechanisms, motors, operating coils, bearings, contacts, relays, flashers and similar components shall be su fficiently large, rugged and accessible to insure reliability and minimum maintenance. All equipment shall be neatly and systematically arranged and mounted to allow thorough inspection while the controller is operating normally, and to permit easy remova l of removable components without interfering with other portions of the controller. Components shall be securely fastened in place to prevent accidental contact with moving parts or electrical power and to permit the cabinet door to be opened and closed without interference or damage to the controller and wiring. Component accessibility shall permit easy access for any needed lubrication. A 30 ampere, mercury contact -type bus bar relay shall be provided for opening the bus bar circuit for signal shutdow n, flashing operation or any other type of controller preemption. All relays associated with the control system shall be of the electromechanical type and designed for heavy, continuous operation. Except for the mercury contactors, all relays shall be mounted on a plug -in base with plug -in mounting. Dial transfer relays shall be jack or plug mounted within the timer unit chassis. Solid state circuitry shall not be used in the dial transfer, offset or split functions. Point to point wiring must be use d on all circuitry. Copper or other track board circuitry is not permitted. The controller dial motors shall be designed for synchronous self -starting operation on 120 volts, 60 Hz, single -phase alternating current. The motors shall have ample torque fo r all requirements of controller operation. Motor and reduction gearing shall be a completely enclosed unit containing a lifetime supply of lubricant. This unit shall not be an integral part of the timer but shall be arranged for easy removal. A maximum of one connector of the screw or bolt type shall be used to hold the timing dial firmly in position. 899 The complete dial unit assembly shall be mounted in a manner which allows it to slide or hinge out of the timer chassis for complete access for inspection and maintenance. Each dial unit shall be furnished with an assembly of five gears (15 per controller). Gears for cycle lengths of 50, 60, 70, 80 and 90 seconds shall be provided per dial, unless otherwise specified. Only one contact (movable) shall be provided per controller circuit. Line side power for these circuits shall be by direct mechanical connection. All make and break contacts shall be of fine silver or a superior alternate material and shall be capable of breaking a current of 15 amperes of tungsten lamp at 120 volts, 60 Hz AC, one half million times without breaking physically or falling to conduct current to the tungsten load when operated 360 times an hour. All signal contacts shall be readily accessible and easily inspected. The movabl e contacts shall be designed to eliminate the possibility of accidental cross connection between adjacent contacts. The contact assembly shall be designed so that the contacts can be arranged or rearranged to cause any signal light circuit to be energized or de -energized during any one of the intervals. All contacts shall be easily replaceable by the use of simple tools. The controller signal common and signal circuit bus shall have an ampacity of not less than 30 amperes. The controller shall provide t erminals, wiring, cams and contacts for 18 circuits complete. Cam sequence switching shall be so designed that it shall not be possible to display a noticeable "dark out" interval at any time following any control function transfer, transfer to flash or a ny preempt transfer. In addition, the closing or opening of signal load contacts shall be positive, without objectionable dark intervals, flickering of lights or conflicting signal indications. Cam shaft advance shall be shaded pole motor or electromagne tic coil and return by gravity assisted spring. The cam rotor mechanism shall provide ample torque to break all bus contact loads, as long as the contacts remain in operational condition. Cam shaft advance impulse shall be actuated by the timer dial unit, or when specified in the Plans by manual actuation. All relays, coils, solenoids and motor windings shall be sufficiently large to insure reliability and minimum maintenance.
715.42.1 2.4-Electrical Connectors: All electrical connections to and from t he timer
unit to the controller back panel shall be made through a 47 pin MS screw -type connector and wiring harness. Each wiring harness shall be at least forty -eight ( 48) inches long or of the standard length specified by the manufacturer for that contr oller type. The harness shall have color -coded leads of labeled sleeves or labeled wires. The harness connections on the controller shall be such that the timer unit may be replaced with a similar unit, without the necessity of disconnecting and reconnec ting individual wires therefrom. Seven circuits in this connector shall be capable of handling No. 12 AWG wire and a maximum of 30 amperes each. Connector pins for these circuits shall be rated at 41 amperes. All other connector circuits shall be rated at 15 amperes (No. 16 AWG) with connector pins rated at 22 amperes.
715.42.1 2.5-Controller Wiring Panel: A controller panel shall be installed on the
back wall of the controller cabinet on which all relays, contactors, breaker receptacles, electrically operated switching devices and other auxiliary controller equipment, not an
Source: West Virginia Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 916–921 of 1,006.