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

IMSA Traffic Signal Technician Level II Exam | Questions and Verified Answers | Grade A | 100% Correct (Latest 2025 / 2026 Update) Question: The traffic field technician is responsible for performing what types of maintenance on signals? Answer: Preventive and Emergency Question: The single most important focus for the traffic signal field technician is? Answer: Safety Question: Three main categories of safety a traffic signal technician is responsible for? Answer: Safety of motorist and pedestrians His or her own personal safety Safety of public and personal property Question: Traffic signal field technicians perform several maintenance and repair functions above the ground and roadway typically using what two vehicles? Answer: Bucket Truck Aerial lift (platform truck) Question: While using a bucket truck or aerial lift what implement provides proper protection for the user? Answer: Protective Harness Question: What responsibilities (liability) does a Traffic signal technician have while involved in repair, testing or maintenance? Answer: Legal liability Dealing with the public Question: It is imperative that the traffic signal field technician maintain comprehensive what of all the steps taken during repair and maintenance of traffic signals? Answer: Documentation Question: What two instances are documentation required for a traffic signal field technician? Answer: Routine maintenance Emergency repair Question: The "word" public usually represents the following individuals (4): Answer: Road users Area residents / Property owners Elected and appointed officials The media Question: Several means of public interaction are (3): Answer: Mail or email Telephone contact Face to face meetings Question: When dealing with the public, keep in mind that the routines of public users may be disrupted for periods of time during construction. How should a traffic signal field technician interact with the public? (5) Answer: Always be polite Be confident when speaking Communicate clearly in understandable terminology Don't argue or threaten Don't provide information if you are uncertain of its accuracy. Question: Traffic signal controller units of todays traffic systems are controlled by what? Answer: Microprocessor Question: The microprocessor is programmed to recognize what? Answer: Input requests from vehicle detection systems Question: A microprocessor takes appropriate action to control intersection what? Answer: Timing Question: A forerunner of the electronic controllers that we have today was the? Answer: Electro-mechanical controller Question: What year where solid state electronic controllers developed to replace the electro-mechanical controllers? Answer: 1970's Question: What two improvements differentiated electronic controllers from electro-mechanical controllers? Answer: More dependable Added many more features Question: What was the standardization that primarily established a pin configuration in the controller and defined a function for every pin? Answer: NEMA TS-1 Question: The NEMA TS-1 has three connectors which where known as: Answer: A,B, and C connectors Question: NEMA TS-1 had how many connectors? Answer: Three Question: The NEMA TS-1 defined every pin for each connector as either what two connection types? Answer: Input or Output Question: NEMA also allowed manufactures to add an additional feature on the fourth connector. What was this connector know as? Answer: D connector Question: What was the D connector commonly used for? Answer: Communications Pre-emption Other special features Question: What three agencies joined together to help develop the 170 controller? Answer: California DOT City of Los Angeles California New York State DOT Question: What controller is an open-architecture based general purpose microcomputer for traffic control? Answer: Model 170 controller Question: What two specifications does the model 170 controller require? Answer: A specific hardware architecture A specific processor Question: How is the Type 179 controller specification similar to the 170 specification?(2) Answer: Open architecture Allows for interchangeability of components Question: What is the primary difference between the 179 and 170 controller Answer: Uses a different microprocessor Question: Who developed the model 2070 controller? Answer: CALTRANS Question: The 2070 was introduced to supersede which controller? Answer: The 170 controller Question: Which controller is compatible regardless of the manufacturer? Answer: The 2070 controller Question: The 2070 provides more functionality than the 170 because of what features?(3) Answer: Additional processing power Ability to program in higher level languages Multiple high speed communications ports Question: Define the acronym NTCIP Answer: National Transportation Communications for Intelligent transportation systems Protocol Question: What is a set of standards established by the consortium for controllers, cabinets and other ITS devices? Answer: The NTCIP Question: The National Transportation Communication for ITS protocol was developed to accommodate what two things? Answer: Needs of subsystems User Services Question: Traffic signal supports and the signal indications and signs that are attached to them should be periodically reviewed to ensure what? Answer: That they are performing the function that they were installed to do. Question: Safety of what two entities is the first concern when performing maintenance on traffic signal supports? Answer: Workers The public Question: The traffic field signal technician should review the work to be performed to ensure that all necessary "what" is ready and available? (2) Answer: Equipment Inventory Question: Traffic signal support poles that have a span wire assembly attached to them are called what? Answer: Strain poles Question: Strain poles are designed to withstand the strain from the loads that are placed on them by what two items? Answer: Traffic Signals Support cables Question: The reinforcing on a concrete strain pole is arranged to primarily withstands loads in how many directions? Answer: One direction Question: The side of the pole that is to be turned toward the load is called? Answer: The load face Question: Overhead signs used in traffic signals are what two types? Answer: Regulatory signs Street name signs Question: How are "blank-out" signs illuminated? Answer: Internally Question: When are blank-out signs only activated? (2) Answer: Specific times of day Specific events Question: Several considerations must be made before actively engaging in work with a lift truck, these include (5): Answer: Positioning if the vehicle in or adjacent to the roadway Establishing a temporary traffic control zone Verification of overhead conflicts Planning the work to be performed Using an approved safety harness Question: Bucket trucks may have a boom that is capable of rotating and extending which is called? Answer: Articulating boom Question: What are some disadvantages of an aerial platform lift?(4) Answer: Only extends vertically Cannot reach as high as boom trucks Must be parked on flat ground Must be positioned directly below work area. Question: The primary purpose of the traffic signal monitor unit is to act as? Answer: Guard against system malfunction Question: If a malfunction is present the monitoring unit will automatically put the intersection into what mode? Answer: Flashing condition Question: An intersection will remain in flash mode until the monitor unit is? Answer: Reset Question: The CMU and MMU checks the controller for what two things? Answer: Proper power Timing functions Question: What will cause the monitor (CMU) to transfer the intersection into flash mode?(3) Answer: Loss of power to the controller The 24 volt DC voltage of the controller is lost Time it takes to change from one indication to another is incorrect Question: What does each conflict monitor have that is unique for that particular intersection Answer: Program card Question: What are short lengths of conductors on the program card called? Answer: Jumpers Question: On the program card jumpers are installed to tell the unit "what" are considered compatible?(2) Answer: Movements Channels Question: For NEMA type controllers positions not having jumpers are considered as? Answer: Conflicts Question: Program cards for type 170 controllers use a "what" as a jumper to wire the positions which are considered conflicts? Answer: Diode Question: Why is it important to periodically review the monitor cards? Answer: To be sure the jumpers are assigned correctly Question: What is used to provide the required flash rate when the signal is in flashing operation? Answer: Flasher unit Question: The MUTCD requires that when a signal is flashed that the light source be flashed at a rate of? Answer: Not less than 50 or more than 60 times per minute Question: What relays are a type of relay that is capable of switching high levels of current? Answer: Mercury Contactor Question: In a traffic signal cabinet the mercury contactor controls the 120 VAC to all of the? Answer: Load switches Question: These devices are being replaced by many agencies due to what type of concerns? Answer: Environmental Question: What are used in traffic signal controller cabinets that are solid-state devices that monitor a mechanical switch or button and report the call status back to the controller unit? Answer: Isolators Question: What are the two basic types of isolator or isolator cards? Answer: AC isolators DC isolators Question: What are the most common isolator cards? Answer: Loop detector cards Question: What are two other special purpose cards? Answer: Video detector cards Emergency vehicle pre-emption Question: Load switches in the controller cabinet receive 24V DC and switch (reroute) the 120V AC to the lamps in the signal head. This potentially reduces: (2) Answer: The number of faults induced into the controller from outside the cabinet. Electrical surges Question: Why do some agencies operate signals in full operation mode for a period of time, then switch to flashing mode? Answer: To preserve the battery life Question: Battery backup system manufactures claim that switching to red flashing operation at "what battery" level percent significantly extends run time? Answer: 40% Question: What type of backup power systems require significant manpower and monitoring during use? Answer: Portable generator Question: Intersections using LED displays use approximately what % of power that incandescent displays use? Answer: 10% Question: What piece of test equipment can be directly connected to many different traffic signal control equipment groups? Answer: Laptop computer Question: What are several of the functions a laptop computer can perform in relation to a traffic signal controller?(5) Answer: Set up equipment Download operational parameters to the equipment Upload signal system software Upload traffic signal timing plans Set up video detection Question: What are the two typical forms of interconnectivity for testing equipment? Answer: Ethernet cable Serial communication cable Question: What type of software program is typically used as a user interface? Answer: Windows - based graphical user interface Question: What is also known as volt/ohm meter or VOM Answer: multi-meter Question: What is an electronic measuring instrument that combines several functions into one unit? Answer: multi-meter Question: A standard multi-meter includes what three main measurement features? Answer: Voltage Current Resistance Question: A multi-meter provides the ability to measure?(3) Answer: DC and AC voltage DC and AC current Resistance Question: What are the two types of multi-meters? Answer: Analog Digital Question: Digital multi-meter functions:(5) Answer: High input impedance Automatic ranging of measurements Automatic polarity identification Sample and hold circuitry Provides a greater number of testing functions Question: Analog multi-meter functions:(3) Answer: Low impedance Fast meter reaction time(measurement time) Provides a quick go or no-go indication Question: What is a device that measures the current flowing through a wire or circuit? Answer: Ammeter Question: Ammeters are also known as?(5) Answer: Clamp-on ammeter Amprobe Clamp meter Current probe Tong tester Question: Which test equipment works by reading the magnetic field around the conductor? Answer: Ammeter Question: What is a unit that a signal technician uses to troubleshoot existing loops and test newly installed loops? Answer: Loop Analyzer Question: What does a loop analyzer measure?(5) Answer: Frequency Relative strength Impedance Change in inductance when vehicle is present Resistance Question: Define TDR? Answer: Time domain reflectometer Question: What is an electronic instrument used to characterize and locate faults in metallic cables? Answer: TDR - time domain reflectometer Question: Because of the sensitivity to impedance variations, a TDR may be used to: (3) Answer: Verify cable impedance characteristics Splice and connector locations Estimate cable lengths Question: What is a single sequence of displays that gives each movement at the intersection a chance to proceed through the intersection on a green indication? Answer: Cycle Question: What is the total number of seconds between the start of a specific display until that display comes up again called? Answer: Cycle length Question: In older electro-mechanical controllers the cycle is sometimes referred to as a? Answer: Dial Question: Describes the direction of approach and the maneuver made at the intersection? Answer: (Vehicle) Movement Question: Vehicle movements are usually recorded in a "what" that is typically included in the plans for a traffic signal? Answer: Timing chart Question: How are vehicle phases typically numbered? Answer: 1 through 8 Question: Which numbers in a vehicle phase a assigned to the through movements? Answer: Even numbers Question: Which numbers are assigned to the left turn movements in a vehicle phase? Answer: Odd numbers Question: Which phases are typically assigned to the major-street through movements? Answer: 2 and 6 Question: The through phases are numbered in which direction and start with which phase? Answer: Clockwise direction Phase 2 Question: An intersection that has four through phases and four protected left-turn phases is said to be an "what" intersection? Answer: Eight-phase Question: What is most commonly associated with a specific vehicular or pedestrian movement? Answer: Traffic signal phase Question: What is the amount of time that a particular indication is given during a phase? Answer: Interval Question: Each vehicular phase is usually comprised of three specific intervals: Answer: Green interval Yellow change interval Red clearance interval Question: What is a series of conflicting phases that occur in an established order, but can never occur simultaneously with each other? Answer: Ring of a traffic signal controller Question: Controllers typically have what two types of ring operation? Answer: Single Dual Question: The number of rings is dependent upon "what" that is required for the intersection operation? Answer: Phasing Question: When are controllers with 3 or 4 rings typically used? Answer: When two or more separate intersections are controlled by a single controller Question: What are phases that cannot happen at the same time because they conflict with one another? Answer: Sequential phases Question: In a sequential series of phases how many phases are served at a time? Answer: One Question: What are used to provide signalization for specific movements that can be made while some of the other phases of the traffic signal cycle are being served? Answer: Overlaps Question: Overlaps are different from other phases because they cannot be? Answer: Independently called into action Question: There are two basic types of overlaps, known as what? Answer: Independent Parent/child Question: What type of signals have detectors and gap counters, and can skip phases? Answer: Actuated Question: The use of fully actuated instead of non-actuated coordinated phases can do what two things? Answer: Better balance volume-to-capacity ratios Decrease split failures Question: What phase allows left turning drivers to cross a conflicting traffic stream with care when there are adequate gaps in the opposing traffic flow? Answer: Permissive left turn Question: When are protected only left turns typically used ?(3) Answer: High volume of through traffic More than two through lanes Intersection with constrained sight distance Question: What phasing occurs when the left turn in one direction gets the left turn arrow before the opposing through movement gets the circular green, then the opposing left turn gets the green arrow after the opposing through is stopped? Answer: Lead/lag left turn phasing Question: What are the two types of flashing mode operation? Answer: Yellow-red Red-red Question: What can be planned for either scheduled late-night flashing or scheduled flashing of a signal that is only needed at certain times of the day or week, or emergency? Answer: Flashing operation Question: What mode causes flashing circular yellow indications to the major street approaches and flashing red indications are shown to the minor street approaches? Answer: Yellow-red flashing mode Question: Flashing red indications are shown to every approach lane to the intersection. This type of flashing operations essentially provides the same type of control as an all-way stop control. Answer: Red-red flashing mode Question: What traffic signal control function is typically enabled by an on-site user via a switch selected inside the police panel? Answer: Stop time Question: What term defines the minimum initial time that the minimum assured green is displayed? Minimum green Answer: Question: The minimum green time is established to provide what to the intersection. Answer: Enough time for vehicles stopped between the detector and the stop line to get started and move into the intersection. Question: On what two factors is minimum green time dependent? Answer: The location of the detector. The number of vehicles that can be queued Question: When establishing the minimum green time consideration must be given to(4): Answer: Pedestrian timing Density operations Controller type Detection design Question: When there are no pedestrian features the minimum green time should be calculated by? Answer: At least equal the minimum time it would take a pedestrian to safely cross the intersection. Question: Typically how many seconds for a left-turn phase? Answer: 3 to 7 Question: How many seconds for a minor street through phase? Answer: 5 to 15 Question: How many seconds for a major street through phase? Answer: 15 to 25 Question: The minimum green time must be long enough to? Answer: Meet drivers expectations as to how long a green interval should be displayed. Question: What is the period of time that the signal displays are red for all approaches? Answer: All-red clearance Question: This interval allows for the intersection to "what" before a green phase starts again? Clear Answer: Question: Factors used to determine the most appropriate time for an all red clearance include: Answer: Type of vehicular traffic Driver characteristics Pedestrian activity in the intersection Question: What is the establishment of a definite timing relationship between adjacent traffic signals? Answer: Coordination timing Question: Traffic signal coordination timings are developed to provide a degree of consistency that should allow traffic to? Answer: Progress through a number of intersections without stopping Question: What within traffic controllers allow for timing plans to transition from one to another gradually so that traffic is not severely disrupted? Answer: Algorithms Question: The amount of time that is allocated to a particular signal phase is the phases? Answer: Split Question: A split includes what three things associated with the phase? Answer: Green time Yellow time Red time Question: What is the transfer of the normal control of signals to a special signal control mode? Answer: Preemption timing Question: Preemption timing has the purpose of servicing? Answer: Railroad crossings Emergency vehicle passage Mass transit vehicle passage Other special tasks Question: Preemption timing control requires "what" of normal traffic control to provide the priority needs of a special task? Answer: Terminating Question: Transit preemption is often called what? Answer: Transit Priority Question: Transit priority can operate by two different techniques: Answer: Green extension Red truncation Question: What has the purpose of transferring the right of way to an emergency vehicle that needs to traverse an intersection? Answer: Emergency vehicle preemption Question: What are the two types of emergency vehicle preemptions? Answer: Stationary Mobile Question: How is stationary emergency vehicle preemption typically activated Answer: When an emergency responder depresses a pushbutton located within the facility . Question: How does a mobile emergency preemption operate? Answer: Transmitter located in the emergency vehicle Receiver located at the intersections Question: How is the preemption input activated typically? Answer: When the transmitter gets close enough to the receiver for the emitted signal to be detected by the receiver. Question: The three stages of drawbridge preemption are? Answer: The clearance of the bridge opening area to permit the gates to be lowered. The omission of phases during the opening. The modification of phase timing after and, opening to clear standing queues. Question: Preemption routines can be directly tied to the bridges via: Answer: Control circuitry Queue detectors, down stream from the intersection on the approach to the bridge. Question: Railroad preemption should always be set to which level of priority? Answer: The highest Question: Emergency vehicles should be set to which level of priority? Answer: Medium priority Question: If multiple multiple preempts are set to the same priority, how are preempts served? Answer: On a first come first serve basis Question: What are the two primary types of transit vehicle-preemption systems? Answer: Optical Radio Question: What is the most common type of vehicle detection at signalized intersections? Answer: Inductive loop Question: Inductive loops create what type of field for detection? Answer: Electromagnetic Question: What is used to create the electromagnetic field for an inductive loop? Answer: Loop detector amplifier Question: What principle is used by a loop for vehicle detection? Answer: Inductance Question: What are some disadvantages of inductance loops? Answer: Can be damaged or broken in areas where freezing and thawing causes the pavement to crack. Can be damaged or broken when a trench is made in the pavement for utility inspection or repair. Installations and maintenance requires closure of travel lanes. Question: An inductive loop assembly consist of? Answer: Detector amplifier Lead in cable Insulated loop wire Shallow slot sawed in pavement Question: The amplifier monitors and registers any "what" that occurs when a vehicle enters the detection area? Answer: Frequency change Question: What setting has to be adjusted to eliminate problems with "false calls" on an inductive loop? Answer: Frequency Question: What term is used to define "false calls" and interference from adjacent loops? Answer: Cross-talk Question: In what instances/areas is the loop sensitivity typically increased? Answer: Presence of bicycles Vehicles with high ground clearance Question: As sensitivity is increased a loop detector has a tendency to do what? Answer: "Lock" or place a constant call Question: Advanced loops are usually square point loop detectors that are placed? Answer: Upstream from the stop line Question: The advanced loops detect vehicles and add what to the cycle? Answer: Extension (passage) time Question: How is advanced loop placement calculated using what factors? Answer: Speed of the vehicles approaching the intersection Safe stopping distance Question: Some advantages of video detection systems include: Answer: Can operate during roadway maintenance or construction Provides a quick way to move vehicle detection zones Can provide video images to a remote location Can be used for incident assessment Doesn't require cutting pavement Question: What can Doppler microwave detectors detect? Answer: Volume Occupancy Classification Speed Question: FMCW microwave detectors can detect "what" in addition to volume, occupancy, classification and speed? Answer: Vehicle presence Question: What device is used for systems that use field master (closed loop systems) to control local intersections? Answer: Dial-up modem Question: How do dial up modems function? Answer: Data transmitted to the dial-up line, then over telephone company's infrastructure back to the central computer Question: Dial-up modems provide what in relation to the transition of data? Answer: Reliability Efficiency Question: What does the use of fiber optic cables provide an agency? Answer: Much higher capability for transmission of data Question: What are the two types of fiber optic cables commonly used? Answer: Single-mode Multi-mode Question: What does POF stand for? Answer: Plastic optical fiber Question: The fibers used in long distance telecommunications applications are always made of which material? Answer: Glass Question: What is used to test the continuity of fiber optic cables? Answer: Fiber optic tracker Pocket visual fault locator Question: What are the two general types of radios available for traffic control systems? Answer: Licensed or unlicensed Question: The annual inventory should include what? Answer: Model and serial numbers of all equipment Date of installation Photographic documentation Question: If a component is determined to be repairable in the field, what is imperative that the field technician do? Answer: Clearly document every step taken in the repair Question: What should field technician repair documentation include? Answer: Model and serial number Status of the replacement component Question: What is the minimum required mode that the intersection should be placed in during repairs? Answer: Flashing mode Question: If during a repair, flashing operation isn't available what step should be taken? Answer: Notify law enforcement to control traffic Question: What are some benefits of traffic signal scheduled maintenance? Answer: Reduce the number of emergency repairs required Reduces delay to the motoring public Reduced travel times Reduced fuel consumption Reduce emissions into the atmosphere Question: In simple terms what is a measurement of raw light? Lumens Answer: Question: What is most significant advantage of using LEDs over incandescent lamps? Answer: Energy savings Question: The IMSA traffic signal field technician certification is valid for how long? Answer: Three years Question: If an equipment restoration effort requires replacement of equipment or specific items, disposition of the removed items should be recorded as: Answer: Sent for repair Not repairable/scrapped Scheduled for diagnosis Question: What is usually the most efficient way to verify that the isolated component is the actual cause of the failure or malfunction? Answer: Testing Question: What is the most important aspect concerning the testing equipment in relation to the field technician? Answer: The technician is familiar with the operation of the equipment and its capabilities