IMSA Traffic Signal Senior Field
Technician III Certification Exam With
Actual 120 Questions & Verified
Answers,Plus Rationales/Expert
Verified For Guaranteed Pass Graded
A+/ 2025/2026 /Latest Update/Instant
Download Pdf
IMSA Traffic Signal Senior Field Technician III
1. What is the primary purpose of a traffic signal cabinet grounding system?
a) Reduce electrical consumption
b) Prevent corrosion of equipment
c) Protect personnel and equipment from electrical faults
d) Improve signal timing accuracy
Correct grounding ensures fault currents are safely diverted, preventing shock
hazards and equipment damage.
2. In a NEMA TS-2 cabinet, BIU stands for:
a) Bus Interface Unit
b) Backplane Interface Unit
c) Binary Input Unit
d) Backup Integration Unit
The BIU in TS-2 systems connects input devices to the controller through the serial
communication bus.
3. Which of the following is NOT typically part of preventive maintenance for traffic
signals?
a) Inspecting detector loops
b) Checking cabinet fans and filters
c) Tightening terminal connections
d) Increasing signal cycle lengths
, Preventive maintenance focuses on hardware and safety, not operational timing
adjustments.
4. MUTCD requires pedestrian clearance intervals to be based on:
a) The posted speed limit
b) Walking speed and crossing distance
c) Average daily traffic volume
d) Peak-hour vehicle demand
Pedestrian clearance times are calculated from crosswalk length and assumed
walking speed.
5. Which type of detector is most susceptible to environmental noise such as rain?
a) Microwave detector
b) Video detection system
c) Acoustic detector
d) Loop detector
Acoustic sensors can be affected by environmental noise like rain or wind.
6. Which type of wiring diagram shows the physical placement of equipment?
a) Schematic diagram
b) Logic diagram
c) Layout diagram
d) Flow chart
Layout diagrams represent physical positioning of signal equipment.
7. In traffic signal coordination, "offset" refers to:
a) Green time length
b) Cycle length difference
c) Time relationship between adjacent signals
d) The clearance interval
Offset controls how signals coordinate by shifting green phases along a corridor.
8. The standard wire color for traffic signal ground conductors is:
a) Black
b) Red
c) Green
d) White
Green insulation is universally used to identify ground conductors.
9. A flashing red signal requires drivers to:
a) Yield without stopping
b) Stop and proceed when safe
c) Proceed with caution without stopping
, d) Obey police direction only
Flashing red is equivalent to a stop sign: stop, then go when clear.
10. Which instrument is best used to measure insulation resistance in field signal wiring?
a) Clamp meter
b) Megohmmeter (megger)
c) Digital multimeter
d) Oscilloscope
A megger applies high voltage to measure insulation resistance.
11. In TS-2 cabinet operation, what does the SDLC stand for?
a) Signal Detector Logic Circuit
b) Serial Data Link Communication
c) System Data Logging Control
d) Signal Delay Line Control
SDLC provides the digital communications backbone in TS-2 systems.
12. The yellow clearance interval is intended to:
a) Provide extra green time
b) Protect pedestrians
c) Warn drivers that the signal is changing to red
d) Allow cross traffic to start
The yellow interval provides a transition warning between green and red.
13. Which NEC article covers traffic signal installations?
a) Article 210
b) Article 250
c) Article 600 and 725
d) Article 500
Traffic signals fall under Article 600 (signs) and 725 (remote-control circuits).
14. Which traffic signal controller feature ensures safe return after power failure?
a) Coordination plan
b) Startup sequence and flash mode
c) Phase skipping
d) Preemption priority
Controllers enter flash after power restoration for safety before resuming normal ops.
15. Fiber optic cables are preferred in traffic systems mainly for:
a) Lower cost
b) Simple splicing
c) Immunity to electromagnetic interference
d) Faster repair time
Fiber optics are immune to EMI, making them ideal for signal communications.
Technician III Certification Exam With
Actual 120 Questions & Verified
Answers,Plus Rationales/Expert
Verified For Guaranteed Pass Graded
A+/ 2025/2026 /Latest Update/Instant
Download Pdf
IMSA Traffic Signal Senior Field Technician III
1. What is the primary purpose of a traffic signal cabinet grounding system?
a) Reduce electrical consumption
b) Prevent corrosion of equipment
c) Protect personnel and equipment from electrical faults
d) Improve signal timing accuracy
Correct grounding ensures fault currents are safely diverted, preventing shock
hazards and equipment damage.
2. In a NEMA TS-2 cabinet, BIU stands for:
a) Bus Interface Unit
b) Backplane Interface Unit
c) Binary Input Unit
d) Backup Integration Unit
The BIU in TS-2 systems connects input devices to the controller through the serial
communication bus.
3. Which of the following is NOT typically part of preventive maintenance for traffic
signals?
a) Inspecting detector loops
b) Checking cabinet fans and filters
c) Tightening terminal connections
d) Increasing signal cycle lengths
, Preventive maintenance focuses on hardware and safety, not operational timing
adjustments.
4. MUTCD requires pedestrian clearance intervals to be based on:
a) The posted speed limit
b) Walking speed and crossing distance
c) Average daily traffic volume
d) Peak-hour vehicle demand
Pedestrian clearance times are calculated from crosswalk length and assumed
walking speed.
5. Which type of detector is most susceptible to environmental noise such as rain?
a) Microwave detector
b) Video detection system
c) Acoustic detector
d) Loop detector
Acoustic sensors can be affected by environmental noise like rain or wind.
6. Which type of wiring diagram shows the physical placement of equipment?
a) Schematic diagram
b) Logic diagram
c) Layout diagram
d) Flow chart
Layout diagrams represent physical positioning of signal equipment.
7. In traffic signal coordination, "offset" refers to:
a) Green time length
b) Cycle length difference
c) Time relationship between adjacent signals
d) The clearance interval
Offset controls how signals coordinate by shifting green phases along a corridor.
8. The standard wire color for traffic signal ground conductors is:
a) Black
b) Red
c) Green
d) White
Green insulation is universally used to identify ground conductors.
9. A flashing red signal requires drivers to:
a) Yield without stopping
b) Stop and proceed when safe
c) Proceed with caution without stopping
, d) Obey police direction only
Flashing red is equivalent to a stop sign: stop, then go when clear.
10. Which instrument is best used to measure insulation resistance in field signal wiring?
a) Clamp meter
b) Megohmmeter (megger)
c) Digital multimeter
d) Oscilloscope
A megger applies high voltage to measure insulation resistance.
11. In TS-2 cabinet operation, what does the SDLC stand for?
a) Signal Detector Logic Circuit
b) Serial Data Link Communication
c) System Data Logging Control
d) Signal Delay Line Control
SDLC provides the digital communications backbone in TS-2 systems.
12. The yellow clearance interval is intended to:
a) Provide extra green time
b) Protect pedestrians
c) Warn drivers that the signal is changing to red
d) Allow cross traffic to start
The yellow interval provides a transition warning between green and red.
13. Which NEC article covers traffic signal installations?
a) Article 210
b) Article 250
c) Article 600 and 725
d) Article 500
Traffic signals fall under Article 600 (signs) and 725 (remote-control circuits).
14. Which traffic signal controller feature ensures safe return after power failure?
a) Coordination plan
b) Startup sequence and flash mode
c) Phase skipping
d) Preemption priority
Controllers enter flash after power restoration for safety before resuming normal ops.
15. Fiber optic cables are preferred in traffic systems mainly for:
a) Lower cost
b) Simple splicing
c) Immunity to electromagnetic interference
d) Faster repair time
Fiber optics are immune to EMI, making them ideal for signal communications.
