IMSA Traffic Signal Technician Level I & II (New 2024/ 2025 Updates) with answers, guaran, Exams of Traffic Control and Regulation

Download IMSA Traffic Signal Technician Level I & II (New 2024/ 2025 Updates) with answers, guaran and more Exams Traffic Control and Regulation in PDF only on Docsity!

IMSA Traffic Signal Technician Level I & II (New

2024/ 2025 Updates) with answers, guaranteed

pass, 100% guaranteed pass/ professor verified

What organization has established requirements for PPE in certain working situations? - ANSWER OSHA/CCOHS Which of the following certifications must be attained first? - ANSWER Traffic signal Tech. Level 1 Upgrades or revisions to the traffic signal are the responsibility of whom? - ANSWER professional engineer What is NOT an example of documentation that can limit the liability of the technician and/or agency? - ANSWER NTCIP What is the single most important focus that the field technician should have? - ANSWER safety For many agencies, what is the least amount of technicians required to perform work with an aerial lift? - ANSWER 2 What is NOT true when it comes to dealing with the public? - ANSWER If you are unsure of the answer, give them the incorrect information so you can keep working What is NOT a function of a modern traffic signal controller? - ANSWER Processing when a vehicle has run a red light and informing the police

What was a major drawback with the first traffic signal controllers? - ANSWER Maintaining the mechanical parts When did standardization of controllers become established in the United States and Canada? - ANSWER 1970s What was limited by the fourth proprietary connector used with the NEMA TS-1? - ANSWER the type of replacement model Which type of controller utilizes a high speed data channel between all major equipment to maximize the functionality and expandability of the controller assembly? - ANSWER NEMA TS-2 Type 1 What greatly reduced wire connections in the controller cabinet with the use of the RS-485 with the SDLC? - ANSWER Bus interface unit What was the intent of developing the ATC specifications? - ANSWER To have an open architecture hardware and software platform for ITS application Which agency developed a communications protocol for ITS systems, field devices and software so basic functionality should be interchangeable regardless of the manufacturer? - ANSWER NTCIP Before beginning work that requires workers or vehicles to be in or over the roadway, what should traffic signal field technicians ensure is in place? - ANSWER Temporary traffic control (TTC) What is NOT a common type of truck used for traffic signal maintenance? - ANSWER dump truck Traffic signals can be attached to Mast Arms using which of the following?

• disconnect hangers attached to the mast arm which suspend the signal
• bracket that is rigidly mounted to the mast arm with a clamping device
• pipe mounts that screw into nipples installed directly into the mast arm
• ALL of the above - ANSWER all of the above

Traffic signal supports are NOT used to display the following items: - ANSWER advertisements Methods of signal supports include what? - ANSWER Truss supports, monotube supports, pedestal supports What is NOT an advantage of attaching signals to mast arms with brackets? - ANSWER allow for the signal to "give" in the wind What are the 2 basic types of booms used on bucket trucks? - ANSWER articulating and extensible Traffic signals are not always where an aerial lift can be positioned properly. What should you always do when operating aerial lifts? - ANSWER Use the stabilizers to provide additional support when the lift is in operation Check for proper operating DC voltage, check for the absence of red on a phase that does not have green, yellow, or walk, check on a simultaneous are functions that are provided by both - - ANSWER CMU and MMU What is the purpose of relays in a traffic signal system? - ANSWER to transfer the outputs from one component to another What device minimizes the amount of voltage that might be available at a pedestrian push button should the button malfunction? - ANSWER Isolator Which of the following combinations would cause the signal to enter flashing mode according to NEMA?

• ANSWER green & yellow yellow & red walk & yellow What feature is included in the 170 or 2070 monitors vs. the NEMA monitor? - ANSWER plug in

Which group of features best describes why malfunction monitoring units are more advanced then conflict monitors? - ANSWER ethernet connections monitoring SDLC communications RS-232 communications port Which type of power supply lines are attached from the power supply (service) inside the power panel?

• 120 v, 40 H, single phase, AC+ and AC-
• 120 v, 60 H, single phase DC+ and DC-
• 120 v, 60 H, single phase AC+ and AC-
• 240 v, 60 H, single phase AC+ and AC- - ANSWER 120 v, 60H, single phase, AC+ and AC- What is NOT an improved feature of the NEMA TS-2 power supply, when compared to the NEMA TS- 1 power supply? - ANSWER 24 V DC power for solar panels At what time can a mercury contactor be disposed of in a typical trash collection receptacle? - ANSWER it can never happen List what is a part of the permanent emergency generator system? - ANSWER uninterrupted supply of power direct connection to the power supply panel external fuel source What is a direct current (DC)? - ANSWER an electrical current that has a unidirectional flow of electric charge A transformer/rectifier is used to supply __________ VDC to electronic components? - ANSWER 24 What type of circuit is the current through each of the components the same? - ANSWER series Voltage is the electrical driver that moves what type of charged electrons through wires and electrical devices? - ANSWER negatively charged

Lightly to moderately doped semiconductor is referred to as? - ANSWER extrinsic Which of the following is a 2 terminal device? - ANSWER diode What is ideal for switching both small and large AC voltages and currents for power control purposes? - ANSWER TRIAC How much current would flow if a circuit has a voltage of 4 volts and a resistance of 4 ohms? (voltage/resistance = current) - ANSWER one amp List semiconductor devices? - ANSWER diodes and transistors SCRs and TRIACs LEDs What is a characteristic that can be applied to a digital multimeter? - ANSWER automatic ranging of measurements To avoid injury, at what voltage should a current measurement NOT be attempted on an open circuit? - ANSWER above the rated voltage of the meter Pertaining to multimeter, what does VOM stand for? - ANSWER volt/ohm meter To make sure that the multimeter does not alter the operation of the circuit when it is used to measure current, the impedance of the meter must be as low as possible. For measurements of around an amp, the resistance of a meter should be what? - ANSWER less than an ohm When using the multimeter, what step should be completed first? - ANSWER ensure that the leads are placed in the correct sockets Most electrical codes require how many ohms to ground for electrical service installations? - ANSWER 25 ohms

Resistance of meters used to measure current are normally? - ANSWER very low What does OTDR mean? - ANSWER optical time domain reflectometer In what type of controller is the cycle sometimes called a "dial" because a rotating dial is used to control the timing of the various signal displays? - ANSWER older electromechanical List 2 things that describe the vehicle movement made at an intersection? - ANSWER direction of approach manuever In usual convention, how are through phases numbered? - ANSWER in a clockwise direction starting with phase 2 Some agencies refer to a combination of movements as a phase. This is also true in some older controller assemblies that operate with what maximum amount of phases? - ANSWER 4 When it comes to barriers for dual ring controllers there are _______ barriers, one for leaving ________ street and one for leaving ________ street - ANSWER 2, major, minor Is this true about an independent overlaps: An independent overlap follows a designated phase - ANSWER no Parent/child overlaps are the most common type of overlap. The overlap is viewed as the ________ because it is only present when one or more phase is active, which is referred to as the ______ - ANSWER child, parent This left turn phase is defined as "both modes occur on an approach during the same cycle"? - ANSWER protected/permissive

The yellow-red flashing mode provides the same type of control as a 2 way stop control where only the minor streets have a what? - ANSWER stop sign In order to ensure fail safe operation , what occurs when a conflict monitor unit (CMU) detects a fault? - ANSWER the flash transfer relays have all of the signals display red What factors might be included in determining the most appropriate time for an all red clearance?

• type of vehicular traffic
• driver characteristics
• Pedestrian activity
• all the choices are correct - ANSWER all the choices are correct What is the time relationship determined by the difference between a fixed point in the cycle length and a system reference point? - ANSWER offset What are the components of volume-density signal timings? - ANSWER gap reduction What are factors of gap reduction allowing for extension/passage time to be reduced? - ANSWER time to reduce Passage time is a function of: - ANSWER distance from the stop line to the detector What should be considered when determining yellow interval timings? - ANSWER formula recommendations from the responsible agency engineering judgement What is developed to provide a degree of consistency that should allow traffic to progress through a number of intersection without stopping? - ANSWER traffic signal coordination timings Splits are typically programmed as seconds but can also be programmed as what? - ANSWER % of the cycle length

All phases of a coordinated operation with the exception of "hold" phases are terminated by what? - ANSWER force offs What periods control when and over what time duration the controller is allowed to service coordinated phases? - ANSWER permissive period Emergency vehicle preemption is designed to do which of the following? - ANSWER clears vehicles from the travel path of an emergency vehicle prevent other vehicles from entering the path that the emergency vehicle has taking prevents vehicles from blocking the emergency vehicles path What signal indications can be displayed at a railroad crossing? - ANSWER 3 section head with red, yellow & green indications What does NOT need to be considered for drawbridge preepmtion of a traffic signal? - ANSWER audible alarms What is NOT a basic component of an optical system? - ANSWER isolators Transit property operates by providing which of the following scenarios? - ANSWER green indication is extended to provide additional green time for the transit vehicle Out of pavement (non-intrusive) detection includes which of the following? - ANSWER microwave video radar With an inductive loop, what energizes the wires placed in the pavement? - ANSWER loop detector amplifier What is an advantage associated with inductance loops? - ANSWER maintenance is simplified

Why is the installation of inductive loop detectors the most labor intensive type of vehicle detections systems? - ANSWER - it uses more materials than other types of detection systems

• the installation requires many workers
• the loop wire must not have any kinks, no breaks in insulation, and have a solid watertight splice to the lead in cable Which type of loop detector offers the greatest range of capabilities? - ANSWER multiple channel loop detectors _____________ are needed to be adjusted to eliminate any detection irregularities due to interference problems with detectors? - ANSWER frequency and sensitivity What types of loops are used for traffic count purposes and for coordinating the traffic signal system based upon real-time traffic volumes? - ANSWER system What is a disadvantage of video imaging detection systems? - ANSWER maintenance requires advanced technical training Which advanced traffic control environment can distributed architecture NOT provide the necessary performance? - ANSWER traffic coordinated control What is the common term for a cable that transmits data between controllers and on-street masters/central computers? - ANSWER hardwire Define POTS - ANSWER plain old telephone service Which of the following is NOT a dip switch setting? - ANSWER cycle length What's true about fiber optic cables? - ANSWER - can transmit data faster than older copper cables
• data can be sent sent in both directions are the same time
• can be utilized for closed circuit television feeds

What is an advantage of single mode fiber optic cable over multi-mode fiber optic cable? - ANSWER has a higher transmission rate than multi-mode fiber What converts electronic data to and from laser light for transmission? - ANSWER fiber optic modems What is OTDR - ANSWER one trial driven reflectometer Limited channel availability, requires line of sight path between antennae, possible interference due to weather is a (disadvantage or advantage) of microwave communications system - ANSWER disadvantage Why is maintenance documentation so important? - ANSWER - to prevent litigation

• historical database
• planning for spare parts and replacement equipment What are the common terms for "trouble calls"? - ANSWER - Complaints
• Report of Failures or Malfunctions
• The Assignment of Personnel to investigate What might be required first if a trouble call does not come in from a reliable source? - ANSWER Make a visit to the site to determine action needed What should be done first after completing the repair and before leaving the site? - ANSWER - Take photographs of the repair
• Document the repair
• observe the operation for several cycles if a field technician was directly informed by a supervisor that a traffic signal was dark at a specific location, what type of liability is this an example of? - ANSWER Actual Notice

What are some of the first steps in observing the intersection? - ANSWER - Watch the signal displays

• watch traffic flow
• check for physical damage and the surrounding area what should be completed after observing the intersection when troubleshooting a problem? - ANSWER Identifying problem what final process must be performed to complete a maintenance call? - ANSWER Documentation What type(s) of legal liability is the traffic signal field tech exposed to? - ANSWER personal liability with regard to safety and tort liability in dealing with the public. What are the four basic types of controller assemblies commonly used today - ANSWER NEMA TS-1, NEMA TS-2, 170 system, and the Advanced Transportation Controller (ATC) what is a "blank-out" sign - ANSWER internally illuminated signs with a static message, only activated during specific times. what are jumpers - ANSWER short length conductors that are installed to tell the unit which movement, or channels, are considered compatible. what is the power supply for the 170 type controller cabinets - ANSWER it's a plug in module that is one component in the power distribution assembly (PDA) what are load switches - ANSWER relays that receive low voltage (24VDC) electric signals from the controller to direct the 120VAC per that illuminates the traffic signal indicators what is a mercury contractor relay - ANSWER tore off relay that is capable of switching high levels of current what is the forerunner of electronic controllers - ANSWER electro-mechanical controllers

what were the three military specification connectors known as - ANSWER A, B, and C connectors what is the basic difference between the 179 and 170 controllers - ANSWER the microprocessor what is a series - ANSWER electrical components connected along a single path What is Ohm's Law? - ANSWER E=IR, R=E/I, I=E/R

• ANSWER