IMSA TRAFFIC SIGNAL SENIOR FIELD
TECHNICIAN III CERTIFICATION EXAM
ACTUAL PREP QUESTIONS AND WELL
REVISED ANSWERS - LATEST AND COMPLETE
UPDATE WITH VERIFIED SOLUTIONS –
ASSURED PASS
1. When performing a pre-maintenance inspection of a traffic signal cabinet,
which of the following is the most critical first step?
A. Checking signal timing plans
B. Inspecting pedestrian pushbuttons
C. Ensuring all power to the cabinet is safely disconnected
D. Verifying the controller software version
Italics: Disconnecting power first ensures technician safety and prevents
electrical hazards.
2. Which of the following wiring colors is standard for AC line voltage in
North American traffic signal cabinets?
A. Blue
B. Yellow
C. Black
D. Green
Italics: Black is typically used for line voltage (hot) in AC circuits; green is
ground, white is neutral.
3. You are troubleshooting a detector that is intermittently failing to call a
green interval. The first step should be to:
A. Replace the controller
B. Verify wiring and detector continuity
, C. Adjust the signal timing plan
D. Replace the detector unit immediately
Italics: Checking wiring and continuity identifies common installation or
connection issues before replacing equipment.
4. Which type of traffic signal controller supports coordinated arterial
progression using time-of-day plans?
A. Isolated controller
B. Master controller
C. Pedestrian controller
D. Flasher controller
Italics: Master controllers coordinate multiple intersections with time-of-
day or adaptive timing plans.
5. During an inspection, you notice corrosion on the cabinet grounding bus.
What is the most appropriate corrective action?
A. Paint over the corrosion
B. Clean and re-terminate the ground connection
C. Ignore if signals are functioning
D. Replace the entire cabinet
Italics: Grounding is critical for safety and proper operation; cleaning and
securing ensures continuity.
6. If a traffic signal displays all red simultaneously due to a controller failure,
the technician should:
A. Restart the signal without documentation
B. Follow emergency traffic control procedures and report the failure
C. Switch to pedestrian-only mode
D. Adjust detector sensitivity
, Italics: All-red failures require immediate traffic safety actions before
technical troubleshooting.
7. The most common cause of signal flashers operating only at night is:
A. Controller software error
B. Photocell misalignment or failure
C. Faulty timing plan
D. Vehicle detection error
Italics: Photocells detect ambient light and control flashers; misalignment
can prevent day operation.
8. When installing inductive loop detectors, the recommended lead-in wire
length is generally:
A. 5–10 feet
B. 10–20 feet
C. 25–50 feet
D. Over 100 feet
Italics: 25–50 feet prevents electromagnetic interference while
maintaining loop sensitivity.
9. A signal technician notices a controller cabinet with temperatures exceeding
120°F. The most immediate concern is:
A. Pedestrian signal visibility
B. Electronic component reliability and lifespan
C. Traffic volume accuracy
D. Detector calibration
Italics: Excessive heat can damage controllers and relays, leading to
failure.
10.Which traffic signal component is responsible for providing a controlled
electrical path for multiple loads within the cabinet?
, A. Detector amplifier
B. Controller board
C. Traffic signal relay or load switch
D. Pedestrian pushbutton
Italics: Relays/load switches route voltage safely to signal heads and other
devices.
11.While reviewing signal logs, a technician notes multiple gap-out events
during off-peak hours. This is most likely caused by:
A. Faulty cabinet grounding
B. Detector sensitivity too low or misaligned
C. Controller firmware errors
D. Pedestrian call conflict
Italics: Gap-out events occur when a vehicle is not detected, often due to
detector issues.
12.In a scenario where a signal must be temporarily removed for maintenance,
the most important traffic safety step is:
A. Schedule repair for off-peak hours
B. Deploy temporary traffic control measures such as cones and flaggers
C. Turn off signals and leave the intersection uncontrolled
D. Notify the media only
Italics: Temporary traffic control ensures safety for motorists and workers.
13.Which standard governs signal timing and operation in the United States?
A. Manual of Uniform Traffic Control Devices (MUTCD)
B. National Electrical Code (NEC)
C. Occupational Safety and Health Act (OSHA)
D. American Association of State Highway and Transportation Officials
(AASHTO) guidelines
TECHNICIAN III CERTIFICATION EXAM
ACTUAL PREP QUESTIONS AND WELL
REVISED ANSWERS - LATEST AND COMPLETE
UPDATE WITH VERIFIED SOLUTIONS –
ASSURED PASS
1. When performing a pre-maintenance inspection of a traffic signal cabinet,
which of the following is the most critical first step?
A. Checking signal timing plans
B. Inspecting pedestrian pushbuttons
C. Ensuring all power to the cabinet is safely disconnected
D. Verifying the controller software version
Italics: Disconnecting power first ensures technician safety and prevents
electrical hazards.
2. Which of the following wiring colors is standard for AC line voltage in
North American traffic signal cabinets?
A. Blue
B. Yellow
C. Black
D. Green
Italics: Black is typically used for line voltage (hot) in AC circuits; green is
ground, white is neutral.
3. You are troubleshooting a detector that is intermittently failing to call a
green interval. The first step should be to:
A. Replace the controller
B. Verify wiring and detector continuity
, C. Adjust the signal timing plan
D. Replace the detector unit immediately
Italics: Checking wiring and continuity identifies common installation or
connection issues before replacing equipment.
4. Which type of traffic signal controller supports coordinated arterial
progression using time-of-day plans?
A. Isolated controller
B. Master controller
C. Pedestrian controller
D. Flasher controller
Italics: Master controllers coordinate multiple intersections with time-of-
day or adaptive timing plans.
5. During an inspection, you notice corrosion on the cabinet grounding bus.
What is the most appropriate corrective action?
A. Paint over the corrosion
B. Clean and re-terminate the ground connection
C. Ignore if signals are functioning
D. Replace the entire cabinet
Italics: Grounding is critical for safety and proper operation; cleaning and
securing ensures continuity.
6. If a traffic signal displays all red simultaneously due to a controller failure,
the technician should:
A. Restart the signal without documentation
B. Follow emergency traffic control procedures and report the failure
C. Switch to pedestrian-only mode
D. Adjust detector sensitivity
, Italics: All-red failures require immediate traffic safety actions before
technical troubleshooting.
7. The most common cause of signal flashers operating only at night is:
A. Controller software error
B. Photocell misalignment or failure
C. Faulty timing plan
D. Vehicle detection error
Italics: Photocells detect ambient light and control flashers; misalignment
can prevent day operation.
8. When installing inductive loop detectors, the recommended lead-in wire
length is generally:
A. 5–10 feet
B. 10–20 feet
C. 25–50 feet
D. Over 100 feet
Italics: 25–50 feet prevents electromagnetic interference while
maintaining loop sensitivity.
9. A signal technician notices a controller cabinet with temperatures exceeding
120°F. The most immediate concern is:
A. Pedestrian signal visibility
B. Electronic component reliability and lifespan
C. Traffic volume accuracy
D. Detector calibration
Italics: Excessive heat can damage controllers and relays, leading to
failure.
10.Which traffic signal component is responsible for providing a controlled
electrical path for multiple loads within the cabinet?
, A. Detector amplifier
B. Controller board
C. Traffic signal relay or load switch
D. Pedestrian pushbutton
Italics: Relays/load switches route voltage safely to signal heads and other
devices.
11.While reviewing signal logs, a technician notes multiple gap-out events
during off-peak hours. This is most likely caused by:
A. Faulty cabinet grounding
B. Detector sensitivity too low or misaligned
C. Controller firmware errors
D. Pedestrian call conflict
Italics: Gap-out events occur when a vehicle is not detected, often due to
detector issues.
12.In a scenario where a signal must be temporarily removed for maintenance,
the most important traffic safety step is:
A. Schedule repair for off-peak hours
B. Deploy temporary traffic control measures such as cones and flaggers
C. Turn off signals and leave the intersection uncontrolled
D. Notify the media only
Italics: Temporary traffic control ensures safety for motorists and workers.
13.Which standard governs signal timing and operation in the United States?
A. Manual of Uniform Traffic Control Devices (MUTCD)
B. National Electrical Code (NEC)
C. Occupational Safety and Health Act (OSHA)
D. American Association of State Highway and Transportation Officials
(AASHTO) guidelines
