IMSA Traffic Signal Technician Level II Exam V2 | (Latest 2025 / 2026 Update) Questions and Verified Answers | Grade A | 100% Correct

IMSA Traffic Signal Technician Level II Exam V2 | (Latest 2025 / 2026 Update) Questions and Verified Answers | Grade A | 100% Correct A traffic cycle / ( cycle length ) definition is ? Is the total elapsed Time between the start of a specific display until the display comes up again. Example ( if the cycle starts at the beginning of a green display it will end when The same green display begins again after the red and yellow displays have been given. The acronym AWG stands for what ? American wire gauge Americans with disabilities act of 1990 (ADA) is ? Requirements ensuring equal opportunity for persons with disabilities and employment, state and local government services, Public accommodations, commercial facilities and transportation The acronym (CMS) stands for what ? Changeable message sign Changeable message sign is for what ? Also known as variable message sign (VMS) and dynamic message sign (DMS) CMS are traffic control devices used for traffic warning, regulation, routing and management, and are designed to affect the behavior of motorist ( thus improve the flow of traffic) by providing real time highway related information What is a (Beacon)? A highway traffic signal with one or more signal sections that operates in a flashing mode. The acronym (ITS) stands for what ? Intelligent transportation systems intelligent transportation systems (ITS) what does it do? Improves transportation safety and mobility and enhances productivity through the use of advanced information and communications technologies. ITS encompass a broad range wireless and wire line communications based information and electronics technologies (ITS) What is a (major street) ? The street normally carrying the higher volume of vehicular traffic The acronym (MMU)stands for ? Malfunction Management Unit Malfunction management unit is ? A device used to continually check for the presence of conflicting signal indications and other malfunctions and to provide an output response to conflict or malfunction. MMU is an advance type of conflict monitor that also communicates and monitors controller function. What is a minor street? That street normally carrying lower volume of vehicular traffic What is "offset" The time difference, or interval in seconds or percentage of cycle length between the start of the green indication of the coordinated phase and the system reference signal What is a "platoon" A group of vehicles or pedestrians traveling together as a group, either voluntarily or involuntarily, because of traffic signal controls ,geometrical or other factors What is a "preemption control"? The transfer of normal operation of a traffic control signal to a special control mode of operation. What is a "Queue length "? Number of vehicles stopped or slowly moving in a line, where the movement of each vehicle is constrained by that of the lead vehicle What is a "signal warrant? A threshold condition that, if found to be satisfied as part of an engineering study, shall results in analysis of other traffic conditions or factors to determine whether a traffic control signal or other equipment is justified Which certification has level II and Level III ? Traffic signal level II bench Traffic signal level II construction Traffic signal level II design Traffic signal level II field Traffic signal level III Bench Traffic signal level III Electrician (field) (Traffic signal phase )is ? Specific assigned timing function in the traffic signal controller. Are phases numbered 1 -8 ? True or false ? True Even number phases are typically assigned to what movements? Through movements Phases 2-6 are assigned to ? Major streets through movements Odd numbers ( 1,3,5,7) phases are assigned to what? Left turn phases An intersection that has four through phases and four left turn phases are considered how may phases together ? Eight phase intersection Each phase is comprised of intervals ? True or false ? True (Interval )is based on? The amount of TIME that a particular indication is given during a phase Another words, the total time assigned to a specific display. An example of an ( interval ) is? " the amount of time that a green indication is given during a particular phase. " (know as a "green _______ )" (Ring) in a traffic signal controller is? A Series of conflicting phases that occur in simultaneously( same time ) with each other What are the two typically ( ring ) that a traffic controller have ? "Single-ring" or "dual ring" What are other ( rings ) that are rarely used ? And when are these types of rings used for? 3 or 4 rings & (used for two or more separate intersections are controlled by a single controller) What is a ( barrier) ? Is a boundary point in the preferred sequence. Barrier that separates something so it won't have in the same time. How many (barriers) does a "dual ring controller" have? Two , one for leaving the MAJOR street and one for leaving the MINOR street. _______ ensure that green indications will not be given to conflicting movement at the intersection at the same time. Barriers What is a ( concurrent phase) ? Are movements that happen at the same time because do not conflict ( collide) with one another. Example of a ( concurrent phase ) A Through movement and a adjacent left turn movement can move on the same time. What is a (sequential phase)? Cannot happen at the same time because they conflict with one another ( collide) In a " sequential phases ? How many movements can it have? Only one phase is served at a time Traffic signal industry has developed basic standards that provide common terms snd concept , but the most important thing is to have an understanding of your_______ Local agency standards What is (traffic signal timing)? The assignment of specific number of seconds for each interval of each controller timing function. ________ are a more detailed assignment of specific portions of time within a phase. Phase intervals phase intervals can be ? Green, yellow , red and pedestrian intervals A green interval is ? Is the total time assigned to the green indication for a phase whether sequential or concurrent. Minimum green or initial green time is? Is the absolute minimum time that the green indication must be displayed. How many basic time components or "sections of time " does a green interval have that equal the entire interval? Three basic time components Most agencies set a standard for a minimum green initial green time. For a left turn face. How long should that minimum green be displayed for ? 3 to 7 seconds Most agencies set a standard for a minimum green initial green time. For a minor street through phase. How long should that minimum green be displayed for ? 5 to 15 seconds Most agencies set a standard for a minimum green initial green time. For a major street through phase . How long should that minimum green be displayed for ? 15 to 25 seconds The common meaning for a passage time/ extension time/ gap extension is? Is the amount of time when a conflicting call is present that the controller will continue to Display a green light after the last vehicle has been detected What is the concept of a "passage time" and "extension time"? Making the time long enough for a vehicle leaving the advance loop to get to a point where It will continue through the intersection if the light turns yellow "Gap extension" concept is? Making the time equal to the length of time between vehicles that is high enough so that the green time is no longer being used in thus it would be better to go to the next phase Maximum green time is ? The highest amount of time that the green light can be displayed when a Conflicting call is present How is "maximum green times "for the various phases of the controller calculated ? It's based on traffic volumes The maximum times can vary during the different portions for a typical day, specially if the controller as part of an area wide coordinated traffic signal system.. is this passage true or false? True Yello change interval does what? It alerts drivers that the green display has ended and that the right-of-way will be changing. The "yellow change interval" must give a sufficient time to allow......... what? Allowed drivers approaching the intersection either to come to a safe stop before reaching the stop line or to proceed into the intersection prior to the display of the rare indication. How is a " yellow change interval calculated? Typically based on the speed of approaching vehicles not the POSTED SPEED LIMIT! "Red Clearance Interval" provides what? A brief period of time between the end of the yellow display on one approach and the start of the green display on a conflicting approach "Basically giving you time to drive to the other side of intersection. Red clearance interval provides a brief period of time. How much time does it give you? 1 to 3seconds How is a red clearance interval calculated ? The distance from the stop line to a point that is clear of conflicting vehicles and pedestrians A "pedestrian head "at a intersection gives the pedestrian what information? The time they need to safely cross the street Pedestrian timings include both ________ & _______________ ? Walk interval and Pedestrian change interval. What is a "walk interval"? The amount of time that is given to the pedestrian that is using the crosswalk to get to the other side of the crosswalk safely. ( it's not related to the time needed to cross the stree) The MUTCD recommends _____ for the " walk interval " but allows the use of walk intervals as short of ______ seconds? 7 seconds and 4 seconds During the " walk interval" , the " pedestrian signal head" displays what symbol? Steady walking person symbol during the walking interval. " pedestrian clearance time" should be sufficient to allow a pedestrian crossing in the crosswalk at the end of the WALKING PERSON symbol to travel at walking speed of ? 3.5 feet per second "Pedestrian clearance time" provides what? enough time for a pedestrian who just enter the crosswalk to reach a safe location at the other end of the crosswalk before a green indication is displayed for other traffic. A pedestrian change interval consisting steps are? 1) UPRAISED HAND (symbolizing Don't Walk ! ) signal indication shall begin immediately following the WALKING PEROSN (symbolizing walk) signal indication. Following the pedestrian change interval. Consisting of a (steady UPRAISED HAND) symbolizing don't walk signal indication shall be displayed for at least 3 second prior to the release of any coming traffic. A " buffer interval consisting of a ? Steady ( UPRAISED HAND ) symbolizing don't walk! The sum of the time of the _______ and _______ shall not be less than the calculated "pedestrian clearance time" Pedestrian change interval and the buffer interval "Buffer space " steady ( UPRAISED hand) shall? not begin later than the beginning of the red clearance interval if used. Minimum recall is? A set for a phase, the controller treat the phase as having a vehicle call whenever a red light is being displayed to that phase. What "recall" will cause the controller to display a green indication every chance it gets and to keep the green light on for at least the length of the time set as the ______ green time for the phase. Maximum recall What "recall" will cause the controller to show a green light to the phase every chance it get, but only for the ______ green time unless there are detection inputs to the controller to extend the phase? Minimum recall "Maximum recall " is what ? Is set for a phase, the controller treats the phase is having a vehicle call at all times "Pedestrian recall" is ? Is set for a phase, the controller treat the phase as having a pedestrian call at all times. What "recall "will cause the controller to show a walk signal and pedestrian change interval to the phase every cycle. "Pedestrian recall" Traffic signal coordination timing is ? Providing a efficient flow of traffic through multiple intersections, the reduction of stops and delays. What are the basic terms that help "traffic signal coordination"? Cycle length , split , offset , yield point, force-off For coordination to happen, all of the coordinated traffic signals along the street must have the??? Same "cycle length" during the same time of the day The common cycle length at each intersection in the system can change throughout the day why ? To handle different traffic Volumes, with higher cycle lengths Generally being used during peak hours and shorter cycle lengths being used during off-peak hours What "split " in traffic signal coronation timing ? Is the number of seconds given to each phase at the intersection What is the "offset" of a cycle? The number of seconds from the common Signal cycle point, to another point. What are some examples for a "offset point "? End of the green indication. End of mainline green, beginning of mainline green, first green The assessment of different_______ at the various intersections is what causes the intersection to work together. "Offset" What is another point in the cycle of a coordinated traffic signal controller where the major street phase is allowed to end? Yield-point A "force-off" is ? A command that forces the Traffic signal controller to end the green display. "Forcing something to change" The "traffic signal system" consist of what ? Traffic signal controllers, detection systems, and computerized control usually from central system. Traffic signal controllers, detection systems, and computerized control are commonly called __________ ? Architecture meaning (format) "Traffic signal system" allow agencies to coordinate traffic signal along what ? A long roadways to monitor vehicular movements, to adjust traffic signal timing based on factors such as weather conditions or special events to manage incidents And even to perform maintenance Of some features of the system from a central location A closed loop system is? Is a distributed processor system with control logic provided at three levels The closed loop system is a distributed processor system with control logic provided at three levels. Those Three levels are: The local controller., the on-street master and the central computer. What are the disadvantages of a "closed loop system"? The inability to easily switch local controllers to a different on-street master in response to varying traffic conditions. What is a "central computer system "? a computer at a centralized location makes decisions and communicates to each individual local controller in the system. The standard traffic signal controller receives commands from where and what happens if communication is lost? Receives commands from central computer, if communication is lost the local controller is forced to revert to its backup plan Communications in Closer loop system typically consist of what ? A twisted repair copper cable or fiber optic cable between local controllers and on street masters and than either telephone modems back to the central computer or I some cases cable throughout the system. "Hardwire interconnect" is ? The common term for a cable that transmits data between controllers and on street masters or between controllers and central computers Copper cables are terminated in local controller cabinets to an _______? "Interface panel" Standard traffic signal controller receives commands from the ? "Center computer system What is another option that can be used for transmitting and receiving signal system data ? Telephone communications "Telephone system" is for what signal system communications "Leased telephone lines" are owned by who? And are assigned to who? Local telephone company and are permanently assigned to and used by the signal system after a contract is negotiated with the telephone company Closed loop systems often use a _________ communication method. "Telephone dial up" "Cell phones" are capable of what ? A signal System communications and are a reliable medium in specific areas. The use of "fiber optic cables " provide what? The agency with a much higher capacity for transmission of data What are the advantages of "radio or microwave communication"? Are the cost & they are less expensive to install & lower susceptibility to loss of communications. The disadvantage of "radio or microwave communication" is Difficultly of transmitting real time or once per second two way communications a "Time based coordination "is placed at ? Independently set up In each controller. What is the advantage of "time base coordination"? Is the simplest system to install becuase a communications infrastructure is not need What is the disadvantage of "time-based communications"? Is that it is extremely unreliable and there are no status reports that can be obtained and a central location What is a "time base coordination" ? The least expensive method of coordinating a group of traffic signals. The "time based coordination" does not require what? Any communications between individual traffic signal controllers. The " flashing mode operation" can be either _______ , ______or _____ ? Planned ( late night flashing) scheduled (Flashing of a signal that is only needed at a certain times of the day or week ) or emergency (when the conflict monitor send the intersection into flashing) What are two types of "flashing mode operation " Yellow-red flash and red-red flash Where would you put a "red-red flashing mode" where there is a all way stop control. Where every approach has a stop sign. ( 4 way stop ) What are the methods for " preemption and priority "? Providing additional green time for specific movements that require special treatment beyond what the standard operation of the signal provides. Which item is for "higher importance"? Preemption Which item is for "lower importance"? Priority Where would you use a " yellow-red flashing mode"? The yellow in the major-street approaches and red flashing on minor streets What typical situations are defined as "preemption "? Railroad, drawbridge, and emergency vehicle __________ What situations are defined as "priority "? Movement of buses,light rail, or trolleys in some urban scenarios What are the differences between "preemption & "priority"? The difference is that "preemption "forces off a phase to provide a green indication for the preempted movement & "Priority "typically extends or calls green phase early to service the movement The "bench technician " is responsible for what? For testing and evaluating suspected faulty components using a wide variety of common And specialized pieces of test equipment to make a decision to repair , send to the manufacturer for repair , return to service or replace the item A "laptop computer" can be connected directly to traffic signal controllers and be used for what functions ? • uploading signal system software • uploading traffic signal timing plans • video detection set up What is a "multimeter"? Is a tool the will measure several different electrical & electronic properties When would you use a "multimeter" ? To check resistance, voltage, or current of a electrical circuit What is a "ammeter/current probe"? It is a device that measures the current flowing through a wire or Circuit. How does the "ammeter/current"probe work? It works by reading the magnetic field around the conductor. When do you use a "ammeter/ current probe" ? To measure the amperes in Circuits in the controller cabinet "Milliamperes meters" are most commonly used to measure what ? DC current and are capable of measuring AC current as well. What does a "megohmmeter " measure ? The resistance or breakdown strength of conductor insulation A "loop analyzer" is a ? unit that a signal technician uses to troubleshoot existing loops and test newly installed loops. A " loop analyzer" measures what ? The frequency and the relative signal strength of the loop And the loop inductance and the change in inductance when a vechile is present And resistance and resistance to ground The typical tests that are performed by the "CMU or MMU tester are ? Red fail indicator, short yellow indicator , AC power failure transfer , restore and power or signal fluctuation. The acronym of "CMU " stand for ? Conflict monitor unit The acronym of "MMU " stand for ? Malfunction management unit What does a CMU or MMU tester do ? Is a device that tests the operation of the CMU or MMU. But also reporting event back to a computer, where the results of the tests may be stored on the hard drives and reports printed for documentation of the tests The documentation provided by the test equipment may aid to what ? In limiting the liability of the maintaining agency Testing the "CMU or MMU is best performed as a ? And should NOT be performed where ? As a bench testing operation and should not be done in the field The "traffic signal controller test set" was developed for what reason ? So that signal technicians could verify whether a traffic signal controller complied with different software and hardware requirements prior to its installation in the field Basically "the controller test set "does what ? Allows the technician to verify whether the controller has been set up correctly The loop detector amplifier tester is a tool that can verify what ? The basic operation of a loop detector amplifier WHEN-can the "detector amplifiers" be checked and WHEN can sensitivity be adjusted and WHEN suspect can be tested to confirm whether or not the should be scrapped? Before installation in the field "Detector amplifiers can be check at what location ? At the bench Whats another tester for a "load switch tester" ? Multi switch tester What is "load switch tester or multi switch tester" ? To verify the correct operation of a load switch. And that the correct current output are within the acceptable range of operation. Some of the load "switch tester or multi switch tester " have the capability of ? Recording the test result. Storing it in a memory card that uploaded in the computer that has a card reader What does the acronym "BIU "stand for ? Bus interface unit What plugs into the cabinet detector card rack and to measure voltage , continuity, and resistance for each internal connection in the cabinet ? Slot testers The "surge suppressor tester detects what ? Short circuits in units, as well as determine that functionality of a suppressor What tool is important in a preventive maintenance program? Surge suppressor tester A "light board "is a device that ? Will test the controller cabinet assembly before it is installed in the field. What tool helps the technician to observe the operation of the signal in the shop and to verify that load switches are receiving and sending the correct outputs? Light board the acronym of "AC" means what ? Alternating current the acronym of "DC"means what ? Direct current The typical traffic signal controller assembly is powered by how many volts and what current does it use ? 120 Volts of (AC) alternating current After the 120 volts of (AC) alternating current enter the power supply, it get disperse within the cabinet ? How many volts of (DC) direct current is used ? 24 volts of direct current (DC) NEMA TS-2 controllers uses how many volts and why ? 12 volts of Direct Current (DC) because it allows the traffic signal control equipment to be more compact & its energy efficient. A circuit that is wired in _______ is one where each component has it own direct path " Parallel " A circuit that is wired in _______ is one where the current goes through ALL of the electrical components of the circuit. "Series " If any component fails within the "series " what happens ? The power is interrupted to all of the components If any component fails in a circuit that is wired "parallel"what happens ? Only that component will be affected by the faliure What is a OHM'S law ? Is a set of formulas that describe the mathematical relationship between the ( voltage (E), current (I), and resistance (R) of an electrical circuit. OHM': law is useful for ? Design and troubleshooting "Voltage formula is "? Current times resistance (E=IR) "Resistance "formula is ? Voltage divided by current (R=E/I) "Current "formula is ? Voltage divided by resistance (I=E/R Technicians need to treat the person to the almost respect regardless of the situation some of these action should be taken include: -Being polite -Speaking clearly and in basic terms -Being confident in speech -Assuring the person that you are -following the correct procedures Technicians need to treat the person to the almost respect regardless of the situation some of these action should NOT be taken include: -Arguing -Threatening anyone -Admitting anything on the spur of the moment -Leaving the site before you have taken every step that you can to resolve the issue The field technician typically performs two different type of maintenance. Those are ? Emergency maintenance, and scheduled maintenance "Scheduled maintenance" is also called ? Preventive maintenance Maintenance involves what ? It's involves of repair or upkeep of the existing equipment and operation. Upgrades involve what? Making additions or revisions to the equipment or operations of a signalized intersection. If a single head became damaged and needed to be replaced by a newer Signal head that was the same size had the same set of indications and will be operating in the same manner and as the existing single head? What will that be considered ? Maintenance If a larger signal head, a signal head with a different set of indications or a signal here that would be operated differently took the place of an existing Signal head it would be considered what? Upgrade What is a " emergency maintenance "? Is something that needs to be taken Care of immediately whenever an agency becomes aware of a problem. Especially if it affects safety. What are information should you have written down in the "documentation " report? Documentation is the date and time the technician or crew arrives at the site Process that the traffic signal filed technician take to determine the cause of failure Corrective action that was taken to restore the normal Operation Disposition of the removed item should be records such as repair parts or not repairable parts Scheduled maintenance. The final step is date and time the signal was placed back to normal operation What are the typical testing equipments used in the field? Multimeter Megohmeter Clamp on ammeter Loop analyzer/tester Loop detector amplifier tester Power quality tester Loop detector Effective determination of the cause of a failure in a traffic signal is called ? Trouble shooting A good five step procedure for troubleshooting is: 1 observe 2 identify 3 determine 4 correct 5 observe again What are some examples for the first step (1) observe ? Watch the signal displays Watch traffic flow Check for physical damage Check the surrounding area What are some examples for the (2) identify ( identify the problems ) ? Only one signal head or indication dark? Physical damage ? Traffic signal cycling property ? Signal timing appear to be causing a back up? What are some examples for the (3) determine ? If a singalong display is out check the lamp or LED If the signal seems to be skipping a movement or timing If a loop appears to be placing a continuous call or no call If the signal is in flashing mode check the manual flash switch The third step (determine) is to perform appropriate what? Visual/physical examinations or diagnostic tests The fourth step ( correct ) in troubleshooting is to ? Replace or repair the faulty components as necessary to return the signal to normal operation When the corrective measures are completed the final step of (troubleshooting) is to ? (Observe again) observe the intersection again for a period of time long enough to feel confident that all of the problems have been diagnosed and appropriately corrected It is very important to fully document what producers in troubleshooting ? Observation,identification , determination,and correction of each problem and then to full document the "after" observation. Why is it "imperative to establish and follow a maintenance program ? To optimize the performance from each traffic signal assembly and each individual component within the assembly All "CMU/MMU manufacturers recommended what ? Annual testing of their products. Signal head lamp replacement is considered what kind of maintenance? & why? An emergency maintenance because it is not performed until the lamp burns off. Agencies find it more cost efficient to replace the lamps on a ________ ? Regularly scheduled basis! Another benefit of replacing lamps on a schedule basis is what ? Is that road users are much less likely to experience dark signals displays which can cause confusion What's also a "regularly scheduled maintenance operation? Lens cleaning Agencies that use LED signal displays still find it necessary to periodically ________ Clean the face of the LED units, even if they don't require replacement _______ are a very important element of a scheduled maintenance program Checklists A maintenance checklist should be developed by who? And why Maintaining agency and so that all necessary tests and procedures are performed for the traffic signal equipment at each intersection in the field The complete checklist for each intersection should be kept as a part of the _______? Agency's record Documentation of the maintenance activities and of the condition of the traffic signal installation and equipment is______ Imperative in maintaining a high level of efficiency and accuracy The most important thing in reporting is ______ Clarity A good Report does not need to be___ ? Wordy or lengthy The reports needs to be accurately described the _____? The maintenance issue, events, or results regarding the visit to the intersection. The report should include exactly what? What activities were performed what actions were taken, and what results were obtained Who is responsible for the components of traffic signal engineering and design ? Responsiblity of a traffic signal design or engineering technician The process of actually installing a traffic signal begins with what? A need (or a perceived need) being recognized by a responsible agency. The installation of a traffic signal requires that certain studies be performed to _______ ? Demonstrate the need. A "traffic signal warrant study "is ? Is typically based on vehicular traffic volumes ; therefore, the initial date collection usually includes traffic counts A "gap study documents "what? The number of available gaps in traffic over a period of time, and the length of time that a sufficient gap is available for pedestrian crossing maneuvers "Automatic counts" typically record what? The through volumes in one direction on segment of roadway for at least a 24hr period "Pedestrian volume counts" are also performed as part of what? of the turning movement counts, typically for an eight hour period "Manual turning movement " counts are typically performed when ? During only the peak period when traffic is deemed to be the heaviest The "turning movement counts record what ? The number of throughly vehicles as well as those that making left or right turns "Traffic counts "are performed for ? Specific time periods,with the times determined by the type of volume data that is being collected Additional research may be needed beyond the collection of traffic volume date and that other research should be what ? "The crash data "at an intersection. To determine whether a traffic signal may be justified based on the crash history Sometimes a traffic generator such as a church school or day care center causes a spike any traffic venues at an intersection during what hours? Off peak hours The traffic signal design process begins when ? A traffic signal warrant study or other related studies and research indicate that a traffic control signal is the appropriate device and if the responsible agency decided that a traffic control signal should be installed. What kind of questions they ask themselves when they pick the right "Signal type" What type of traffic signal supports will be used? Will the traffic signal be coordinating with other nearby ones? Is there a computerized traffic sign system in the area? Will emergency vehicle, railroad or other types of preemption be required ? Etc A "soft dig " is a what and helps ? Is a process where the utilities are located and exposed by a qualified company, and the location are recorded by a surveyor. A " soft dig prevents what? A high potential for damage, disruptions vital services, or lost importantly, injury to or death of workers of the public "Traffic signal phasing design process should be considered when? Early in the design process so that the traffic signal installation will adequately address the needs of the various traffic movements at the intersection. The designer in "phasing" should coordinate with who? &why? Maintaining agency& in the case of coordinated or computerized systems to ensure compatibility with existing phasing conventions to promote consistency with the system. Before the bidder Prepares a bid price that plans preparation should have ? depict a graphic layout of the traffic signal on the proposed site and provide the pertinent information regarding quantities and specification "Special provisions " are an ? Additional document that is often added to a set of contract documents to provide the contractor and inspector clarification on specific items or procedures that would only be applicable to the specific project Almost all of the_____________In the United States and Canada have developed special standards and specifications for traffic signal installation? Department of transportation What does the "single designer"need to be familiar with? Standards and specifications EEO participation requires the contractor to maintain a percentage of what? Minority worker on the project and to keep records that verify compliance. On projects are installed on state DOT right of ways all equipment and materials must meet the specifications established by who ? DOT The purpose of traffic signal inspection is to provide what? A record of construction and to document results Of test to verify the installation meets the requirements of the plans and contract documents. The highest priority is to installtraffic signal know that is what? Safe for all users Hybrid system is? Allows central control in the sense that the computer at the control center can communicate with and change the timing of individual traffic signal controllers in the field Stand alone traffic signal installations are typically priced higher per intersection than multiple installations primarily because why? The costs for mobilization of equipment and personnel differ greatly between single and multiple installations Labor requirements) contractors are provided a Certain number of hours for what? That are used got hiring and training personnel in the traffic signal construction field. Participation in this training effort by the contractor is required The contractor is responsible for keeping track of this activity and adjusting the pay accordingly True or false Who is responsible to review all materials entered into the project to ensure compliance with the requirements? Project administrator Typically the department has a list of approved products and the materials and equipment but must be what ? Must either be on the list or pre approved by the department prior to entering into the project The purpose of traffic signal inspection is to provide what? A record of construction and to document results of tests to verify that the installation meets the requirements of the plans and contract document Potentially dangerous in situations should be avoided to the maximum extent possible when ? Both during construction and after the Signal is operating What happens when there is a low quality signal inspection or with no inspection at all? A traffic signal might begin experiencing operational problems soon after it is completed and excepted What are all indications of a low quality signal installation caused by poor inspection? Failed loops, repeated conflict monitor activations, and an excessive number of trouble calls are all indication High quality, full time traffic signal inspection personnel are especially important for items that will be what? Be buried underground and under the pavement such as Pole foundations conduits and loop detectors Several specific technician disciplines are needed in traffic signal of these specific disciplines is_________? Traffic signal construction Who is responsible of how to construct and install the main components of a traffic signal? Traffic signal construction technician In most common situations Traffic signal will be constructed by who ? Contractor In cases where a governmental agency constructs traffic signals using their own in house employees, the process will generally be what ? The same and the word " agency" could be substituted for " contractor" in the discussions Typically once a contractor has been given a notice to proceed what happens next? The construction phase begins and the traffic signal construction technician will begin to oversee these elements What "start up" items that need to be completed by the contractor prior to beginning the actual physical construction ? • construction permit procurements • utilities notifications and coordination • public awareness (if required by the agency or municipality • Development and approval of a traffic control plan for the maintenance of traffic • traffic signal materials and equipment submitted to agency for approval • procurement of traffic signal materials and equipment from vendors • scheduling of contractor and subcontractor crews • Mobilization of personnel and equipment to the project site What EQUIPMENT that a traffic signal construction technician can expect to use ? Digger truck Boom truck Crane for concrete Water truck for slurry mixing Bucket truck Backhoe Horizontal boring machine Trencher What TOOLS that are commonly used for traffic signal construction? Large volume air compressor Motor driven pavement saw Jackhammer Power drills Cable tensioner Ratchet type electrical crimper Transit level of laser level Concrete vibrator Common hand tools( pliers,wire strippers, saws, wrenches, screwdrivers and cable cutters In some cases where concrete strain poles are direct buried, a certain volume of what is required ? Concrete backfill is required to provide additional stability for the pole Direct buried excavation is typically what and why? Over-drilled & such that there is sufficient room for compaction of the backfill material but the bottom of the support itself is actually buried below ground What kind of material may be used for the backfill ? The same removed material Backfill should be compacted to a what? To a density equal to the original condition or greater What Traffic signal supports that require some type of foundation ? - Mastarms - steel strain poles -trusses - mono tubes - pedestal poles for vehicular signals - Pedestrian signal pedestals Foundations are sometimes referred to ? "Footers or bases" Foundations are typically constructed by what ? Concrete How are these concrete structures reinforced with? "Steel rebar and the anchor bolt what's are cast into the top of the concrete The majority of the larger structure foundations are required to be poured _____? In place. Some agencies and departments of transportation allow what ? Pre cast foundations for small structures What installation support is much less labor intensive than installation of a mast arm signal support? Pedestal support How many people it take to install a pedestal support ? Two people What do you need for a installation of a "mast arm signal support ? Require a book truck or crane along with operators and a ground crew, and a bucket truck driver and operator and traffic control personnel to protect the safety of the public and the workers What is typically installed AFTER the signal supports are in place? Vehicular traffic signal heads Some contractors elects to install traffic signal heads on a master arm before it is attached to the upright part of the assembly. True It's should be noted that to prevent driver confusion, all (vehicular signal heads) should ___ ? Remain covered after installation until the signal is ready to be turned on to flashing or full operation Traffic signal heads (overhead signal heads) that are positioned over the roadway are typically installed ? On span wires, mast arms trusses or monotubes. The alignment of the signal here over the roadway lanes is an? Important component and should be checked prior to drilling the mast arms and/or attaching the brackets Signal heads that tend to swing back and fourth during windy conditions are called ? "Free-swinging" signal heads Signal head that are mounted on mast arms,poles,or pedestals are often called ? "Rigid-mounted" Span wire installations typically require what? Signal head disconnect hangers attach directly to the span wire( or messenger wire) Regardless of whether the span wire assembly has single point or dual point attachments, the disconnect hangers are for? Integral support mechanism for the traffic signal heads Another word for "span wire" is ? Messenger wire The signal cable is attached to the span( messenger ) wire as well, and may be what? Terminated in the disconnect hangers, or inside the signal head on a terminal block or terminal strip How are traffic signal head attached to mast arms or monotubes? attached by means of a bracket that is "rigidly mounted" to the mast arm or monotubes, or by means of a steel pimple nipple welded into that mast arm or truss tube. the signal head are than attached to? To the bracket or pipe nipple The "signal cable" is placed where? Inside the mast arm or monotubes and enters the signal head through the bracket Cable termination in these mounting (mastarms monotube and truss) types is usually on a ? Terminal block or strip inside the signal head How are traffic signal head that are attached to "trusses" where may they be attached too? Below the truss, by attaching a disconnect hanger to the truss with a cable or band assembly or within the truss frame work. Using either bracket or disconnect hangers attached to the top portion of the truss. The signal cable for truss support is usually attached where? Attached to the truss beams and is terminated in the disconnect hanger or signal head. Traffic signal head that are mounted on "pole top "poles typically require what? Less heavy equipment for installation, but require specific hardware and brackets Traffic signal heads that are attached to the "side of pole" are typically mounted with? The same type of bracket that used to attach signals to MAST ARMS! structures side of pole" are typically mounted with the same bracket of what support ? Mast arms support Why is the "side of the pole" pole drilled ? Such that the signal cable inside the pole enters the signal head through the bracket, and then is terminated inside the signal head. Banding is a variant installing where ? Steel bands are used to attach the signal to the side of the pole. The pedestrian signal heads need to be installed within _______ Established guidelines and standards so that they are readily visible to pedestrian at the far end of the crosswalk Pedestrian signal head are typically mounted on signal poles if? The poles can be installed in close proximity to the ends of the crosswalks If the single pole CANNOT be positioned near the ends of the crosswalk, pedestrian signal heads are usually ? Mounted on "pedestals " that are placed in the appropriate position "Pedestrian signal heads" can be mounted on the top of a pedestal, in either_____? A one way of two way configuration How is the signal cable installed for a pedestrian head? Enters the pedestrian signal heads from the inside of the pole and through the mounting bracket What are some type of brackets for "pedestrian signal heads "that are mounted to the sides of traffic signal support? Pipes fabricated to specific dimensions and criteria so they will accept standard pedestrian signal heads Typically mounting hardware is available for ? One way or two way installation Another word that is "collectively reffeded to ( the controller, the cabinet, and other devices within the cabinet is? Controller assembly The "controller assembly" should be located within where ? The right way and if possible, away from the edge of the roadway or BEHIND A SIGNAL POLE for added protection from errant vehicles The cabinet door should open how? Such that the door opens AWAY FROM THE INTERSECTION! and in a position that gives the field technician the greatest possible view of the intersection when working with components inside the cabinet for maintenance or troubleshooting When a new controller assembly is installed what should you do ? An inventory of the equipment should be taken. Typically what does the inventory consist off? Consist of recording the name of the manufacturer along with the serial and/or model numbers of the cabinet, the controller, the conflict monitor unit (CMU) or malfunction unit (MMU) and any other equipment that is not installed by the manufacturer of the cabinet and delivered in it What are some examples of other types of equipment that should be inventoried? Video detection monitors ,external communications modems and shelf mounted or rack mounted detector amplifier units. What test should be done FIRST prior to installation in the field ? Bench tested What test should be performed for proposed for traffic signal test? Basically what test is should be done in the field ? Field test What is a "bench test" ? A test performed with the equipment that is proposed for the traffic signal installation. Testing in the shop What is the second field test ? Test is performed after the traffic signal construction is substantially complete The testing of the controller cabinet assembly is usually performed in two stages ? What stages are they? Bench test and field test Many local agencies prefer that their technicians perform these bench test and field tests with who? And why Contractor present to perform any equipment replacement or adjustment that might be required to make the installation acceptable What wiring is a major component of the intersection wiring ? Traffic signal cable What wiring is also part of the intersection wiring? Wiring associated with the Vehicle detection system, street lights on the signal poles or with communications to another controller or to a central computer All of the wires or cables that enter the traffic signal controller cabinet must be ? Labeled The signal cable conductors are typically labeled with ? The signal phase of the display that they control Inductive loop detector lead in cables are typically labeled why? So that the technician can identify the physical location of the loop at the intersection, using conventions established by the DOT or local agency Video detection cables Are typically labeled ? With the camera number that they control Pull/junction boxes and pole hand hole require what ? Require some type of labeling Labels are coded to indicate what? (1) function (2) source and (3) destination of the cables and wires One somewhat common method of "coding " is the use of ? colored Tape, or a number of tape bands to indicate the cable route and termination point The typical test for traffic signal conductors wiring are ? (1) fictional such as the connection to the proper signal display, (2) induced voltage and (3) continuity Traffic signal installations require that the signal cable have additional what? Conductors "Conductors" are typically referred to as what? "Spares" Where are usually "spare conductors " terminated? In the controller cabinet and in the disconnect hanger or traffic signal head assembly Depending upon the agency that the technician is serving "spares " that enter the controller cabinet are either terminated in the ? Bonding bus, neutral bus or simply bundled together and taped or capped "Spares" that enter a disconnect hanger are typically terminated in the ? Terminal strip and spares in a traffic signal head assembly are not connected to the assembly but the ends are individually capped or tapped improperly installed or adjusted vehicles detection system can cause what ? Can cause the traffic signal to not function as intended In case of video or microwave or radar detection the alignment of the detection units is extremely important ? True or false True What type of vehicle detection systems installation most labor intensive ? Inductive loop detector To achieve a successful loop assembly installation the loop wire must be installed WITHOUT any ? Kinks in the wire, without any breaks in the insulation, with properly twisted wire between the loop snd the splice and with a solid water tight splice to the lead cable The saw cut for the "loop detector " must be free of what? Of dust and debris prior to the installation of the loop wire snd the sealant must encapsulate the loop wire correctly The video detection cameras installation must be ? Must be aligned and aimed correctly for optimum performance What else is important for the video detector installation? Video detection zones must be properly established and the video imaging processor must be properly programmed to provide correct input to the signal controller The " microwave or radar detector installation units require what for installation ? Require alignment and aiming similar to the video detection units but input into the controller cabinet is processed in a fashion similar to that of the inductive loop sectors Typical procedures for traffic signal inspection and turn on require who to be there ? The representatives of the permitting agency, the maintaining agency, the contractor , and the inspector meet at the intersection for the final inspection. The signal can be placed into permanent stop and go operation until ? It has been determined and agreed upon that all items are complete or that the remaining items that have been placed on a punch list will not prevent the traffic signal from functioning as designed and intended Most agencies require that a new traffic control signal be initially activated during the off peak traffic hours and those days are ? Tuesday Wednesday or Thursday Why traffic signal be initially activated during the off peak hours hours? So that any remaining problems that shoe up can be corrected before the peak period and before the weekend arrives so that repair crews with be quickly available if needed A complete installation of a "controller cabinet assembly includes ? The cabinet and controller. , associated components, the main panel( back panel) and sub panels. There are three typical mounting method that are used for controller cabinets and those are ? Pole mounted,pedestal mounted and ground mounted What kind of base for a controller cabinet that is ground mounted cabinets usually required to have ? Concrete, polymer concrete or fiber glass pad that is either poured in place or installed as a pre cast unit, is required for ground mounted cabinets Controller assemblies evolved into what? Integrate several highly-sophisticated electrical and electronic devices that perform functions such as changing the signal indications, collecting and analyzing vehicle count and classification data, assisting with incident management tasks, proving coordinated traffic signal system control and communicating with other associated controller or with a central computer What are three basic types of "controller assemblies" commonly used ? NEMA TS 1 , NEMA TS 2, and 170 These NEMA TS 1 , NEMA TS 2, and 170 identifications describe what ? The cabinet type and internal components of the controller cabinet The peripheral (specific) equipment that is installed in the cabinet must be compatible with what? Specific cabinet Such as "load switches are interchangeable between what? Controller assembly types Such as "detector amplifiers " require what to operate ? Require adapter to operate in different assembly types The acronym ATC means ? Advanced transportation controller The newer type of cabinet and controller that is becoming more popular is ? ( ATC) advanced transportation controller The (ATC ) advanced transportation controller provides what? An open architecture hardware and software platform that can support a wide variety of intelligent (ITS ) transportation systems applications The (ATC) advanced transportation controller standard defines ______ A controller that can grow with technology The 2070 controller was designed to be used in _______ All of these cabinets/ controller assemblies and to accept multiple software platforms If NEMA (cabinet) is specified and a NEMA (controller ) is installed then the peripheral equipment must be ? NEMA compatible If a 170 cabinet is installed the equipment installed in it is 170 as well it must be ? Compatible for functional operation. Some instances however where adapters have been-utilized to combine NEMA AND 170 controller or interface components for specific applications resulting in a ? Hybrid controller assembly What are the differences between "NEMA" controllers & the "type 170 or 2070" controllers ? NEMA controllers operate using software that is specific (same) to the manufacturer of the controller and cant be changed and type 170/2070 controllers operate using software that can be changed NEMA TS-1 , NEMA TS-2 and 170 controllers assemblies include what ? It includes there specific type of signal control and there associated software What is another differenc between the NEMA cabinet and 170 cabinets ? Is that NEMA cabinets typically have several stand alone complete that require connection with harness pre wired into the cabinets. Whereas the 170'cabinet are configured so that modular type composts can be easily replaced by unplugging the defective components and plugging a new one into the slot Smaller intersections that are not connected to computerized systems may be able to be controlled with ? Minimal equipment in a small cabinet Larger complex intersections that are in signal system require what size of cabinet ? Large cabinet NEMA cabinets are often identified by ? "Enclosed type " and may have a number designation, a letter disinflation or a combination of both 170/2070 cabinets are usually identified by ? A number designation, with some of the numbers being followed by a letter of the alphabet A " P" cabinet from one manufacturer should be the same size as a ? " P" type cabinet from another manufacturer A type "V" cabinet should be identical in size _______ No matter which manufacturer supplies it The acronym (ITE) means ? The institute of transportation engineers The institute of transportation engineers (ITE) advanced transportation controller (ATC ) family of standard is intended to ? Provide open architecture hardware and software platforms to support a wide range of intelligent transportation systems (ITS) applications requiring a filed implementable controller The conflict monitor unit (CMU) or malfunction management unit (MMU) is an ? Electronic device that monitors the operation of the traffic signal controller for the primary purpose of preventing conflicting traffic signal indications from being displayed If the CMU or MMU detect that conflicting displays such as a northbound through green and westbound to southbound green left turn arrow are on simultaneously what will it do? Will immediately switch the traffic control signal into flashing mode operation Technology has developed to the degree that modern MMUs are capable of what? Of maintaining event log records, records of voltage fluctuations and communicating in real time with computerized traffic signal system control equipment and personnel, while at the same time diagnosing faulty signals and offering trouble shooting MUTCD requires that when a signal is flashed mode that light source be flashed at a rate of what ? Not less than 50 or more than 60 times per minute Load switches are called ? Switch packs in 170/2070 controllers Load switches are relays that ? Receive low voltage (24VDC) electric signals from the controller to direct the high voltage ( 120 VAC) power that illuminated the traffic signal. Each load switch consists of what ? Of three outputs into the field load bay that can be connected to field terminals The electrical power supply or "power service usually originated at ? A point near the intersection where electrical power is obtained from the local power provider Power service may be either? Underground or overhead, depending upon agency preference What are the basic components of " overhead power service " Power supply wires Conduit riser and weather-head Meter housing Disconnect housing What are the basic components of " underground power service"? Pull box or boxes Conduit Power supply wires Meter housing Disconnect housing Meter and disconnect pole Before being fed to electrical devices within the cabinet_______ The electricity from the power company is passed through a surge suppressor and a radio interference suppressor placated on the panel This power panel is a power distribution center for the devices in the cabinet and is not what? Not to be considered as the main disconnect for the power service supply from utility What are two common types of "relays " ? Flash transfer relays and mercury compactor relays Flash transfer relays transfers ? The output of the flasher units to the field indications when the traffic control signal is operating in the flashing mode Mercury contractor relays are ? A type of relay that is capable of switching high level of currenc In a traffic signal cabinet what does the mercury contractor control ? The 120VAC to all of the load switches Preemption equipment allows what? Allows the normal operation of the traffic signal to be temporarily altered to respond to a particular type of vehicle or particular situation Most equipment used in preemption and priority operations are located where ? Outside of the controller cabinet Preemption and priority are considered what ? Auxiliary or additional equipment that is not always typical to a controller cabinet What is the priority is the basic principle in preemption? Is that the controller is advised that a specific situation is occurring that it must react to by altering the normal traffic signal Phasing operation What are some scenarios of manual activation ? Responded manually activates a push button inside the fire station that sends the notice to the detector interface which in turn direct the controller to provide the required phasing for the emergency vehicle to enter the traffic stream What are some scenarios optical or acoustic activation ? A transmitting device mounted in or on a vehicle sends a signal to the receiver mounted at the intersection and the receiver sends the notice that the vehicle is approaching and requires a cycle change which the controller initiated upon receiving the signal from the interface unit The basic components of the preemption and priority equipment include what ? Transmission unit or push buttons, wiring or coaxial cables from the receiving device to the controller some type of interface equipment and controller cabinet wiring that will accommodate the preemption or priority plan required in the design plans Auxiliary or additional equipment that support communications include ? Communications interface panel Cable punch down block Fiber optic cable "tray" External modem or internal modem (in controller? Battery back up system are typically used where and when ? In high urbanized areas or on main thoroughfares to provide an extra degree of safety when the power supplied by the power company in unavailable When a power outage occurs the back up battery is being supplied for power what does the back system do ? Flashing mode operation allows the major street traffic to proceed by displaying a flashing yellow and stops the minor street traffic by display a flashing red. Typical signal Operations times for signal installations consisting of all ? LED heads range from 2 to 6 hours of full operation automatically followed by 4 to 8 hours of flashing operation Some agencies have begun using what ? Emergency generators How is the emergency generator installed? A connection is installed between the power supply and the electrical power service that allows the