IMSA TRAFFIC SIGNAL TECHNICIAN 1 EXAM

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IMSA TRAFFIC SIGNAL TECHNICIAN 1 EXAM

QUESTIONS AND VERIFIED DETAILED

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An intersection that has four through phases and four left turn faces is what ?Said to be in "eight phase intersection" What is a interval ?Is the amount of time that a particular indication is giving during a phase What is a "rings"?is a serious of conflicting phases that occur in an established order, but can never occur simultaneously ( in the same time) with each other.There are two types of "rings " for controllers they are typically what ?"Single ring" or "dual ring" The number of rings is depending upon what?The phasing that is required for the intersection operation What is the boundary point in the preferred sequence of a dual ring controller that both rings must simultaneously ( at the same time) cross?Barrier On a dual controller, there are two barriers and what are those ?Two barriers

-One for leaving the major street and -one for leaving the minor street 1 / 4

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Traffic signal controllers that operate in a fully- actuated or semi-actuated mode use some type of what ?Vehicle detection equipment What does vehicle detection system do ?Detects vehicles on the intersection approaches and sends a message or call to the controller that an approach needs to receive a green indication. So they can proceed.How do loop detectors operate on what ?Inductive Loop detectors can be installed in a variety of configurations and shapes including?Square, rectangular,double rectangular(quadrupole),diamond, circular and octagonal What is another name for a double rectangular loop dectectors?

• quadrupole)

Regardless of the configuration of the loop,and the placement of the wire in the loop requires multiple what ?Wraps or "Turns" of wire to form the loop

• foot by 6 foot loop might require how many turns?
• turns

6foot by 20 foot loop might require how many turns?

• turns

6foot by 60 foot loop might require how many turns?Require 2 turns What are the advantages of inductance loops?1) less initial cost in comparison with higher technology type of detection systems 2) simplified maintenance in the components are easily diagnosed and replaced 3)the detection area placement is more flexible because it can be curved or angled to accommodate different geometric configurations of approach lanes.What the disadvantages of inductance loops? 2 / 4

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1) loops can be damaged or broken in geographic areas where freezing and thawing causes the pavement to crack 2) loops can also be damaged when trench is made in the pavement for the utility installation or repairs 3) loop installation and maintenance requires closure of travel lanes Principle components of an inductive loop detectors system include?One or more turns of insulated wire wound in a saw slot in the pavement; A lead in cable from the loop to the controller cabinet and a detector electronics unit (amplifier) Inside the cabinet When a vehicle passes over the loop or is stopped on the loop the decreases what?Inductance of the loop Inductance loops work like ?A metal detector as they measure the change in the field when object pass.The most common loop warrior sizes range between? What ?#12 AWG & #16 AWG the acronym of AWG stand for?American wire gauge What is the standard of "American wire gauge "?is a standardized wire gauge system used since 1857 for the diameters of round, solid, nonferrous, electrically conducting wire. (American Society for Testing and Materials) Loop wires are typically installed in ?Slots cut into the roadway with a pavement saw Loops sensitivity is what?A measure of the amount of inductance Change caused by the presence of a vehicle may decrease base on the debt into the pavement that the loop is buried What's another loop detector?Performed loop The shape Of a performed loop are?Sometimes circular in shape like a hula hoop before they are placed in the roadway 3 / 4

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The performed loop requires?A wider slot in the pavement and they require a circular slot which is harder to cut.Loop wires are protected by what?An protective layer and there are likely to fail or break then non-perform loops What kind of components does a loop lead in cable have?• outer jacket • shield •. conductors •. Drain The loop lead in cable which is terminated on the loop detector panel in the single control cabinet is the portion of what ?the portion of the loop detector assembly that connects the loop wires to the controller cabinet Video image detection systems are to?Detected vehicles at signalized intersections Video imaging detection system equipment include ?Video camera A monitoring and image storage module Detection modules A programming device and it software Cable between the camera and the video image processor Peripheral equipment The video image processor is used to ?Detect the presence of vehicles in optical detection zones.The advantages of video detection systems are ?

• Capable of operation during roadway maintenance or construction activities such as milling

and resurfacing

Can provide video images to a remote location for traffic monitoring purposes

Can be used for incident assessment and management in addition to vehicle detection.

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