IMSA Traffic Signal Senior Field Technician III
Certification EXAM ALL 250 QUESTIONS AND
CORRECT ANSWERS LATEST UPDATE THIS
YEAR
This document contains 250 verified questions and answers for the IMSA Traffic Signal Senior
Field Technician III Certification Exam. It is designed for study and exam preparation purposes.
Each question includes multiple-choice options, the correct answer, and a brief rationale
explaining the reasoning behind the answer.
The exam focuses on traffic signal operations, TS2 controller systems, loop detection, pedestrian
signals, safety protocols, and advanced traffic management systems (ATMS). Candidates are
advised to review both the questions and rationales thoroughly, as understanding the concepts is
essential for success in practical and written certification examinations.
Disclaimer: This document is for educational purposes only and is not affiliated with IMSA or
its official testing services.
1.
Q: What is the primary purpose of interconnect systems in coordinated traffic signal operations?
A. Improve pedestrian crossing times
B. Reduce maintenance costs
C. Synchronize signal timing across intersections ✅
D. Monitor vehicle emissions
Answer & Rationale: C – Interconnect systems allow real-time communication between
controllers, ensuring coordinated signal timing along corridors for smooth traffic flow.
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2.
Q: What is the most appropriate tool to test an inductive loop detector’s functionality in the
field?
A. Digital voltmeter
B. Loop tester ✅
C. Megohmmeter
D. Oscilloscope
Answer & Rationale: B – A loop tester is specifically designed to test inductive loops for
continuity and functionality without damaging components.
3.
Q: In a NEMA TS2 cabinet, which component facilitates communication between the controller
and detector racks?
A. Bus Interface Unit (BIU)
B. Malfunction Management Unit (MMU)
C. Input File ✅
D. Conflict Monitor
Answer & Rationale: C – The Input File houses detector input terminals and facilitates signal
transmission from loops or sensors to the controller.
4.
Q: Which of the following is a common cause of intermittent traffic signal controller resets?
A. Short loop wires
B. Pedestrian push button faults
C. Power supply fluctuations ✅
D. Conflicting signal phases
Answer & Rationale: C – Fluctuations or surges in power can trigger controller resets, affecting
signal operation intermittently.
5.
Q: Which communication protocol is most often used in advanced traffic management systems
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(ATMS)?
A. SMTP
B. FTP
C. TCP/IP ✅
D. POP3
Answer & Rationale: C – TCP/IP is the standard protocol suite used for data communication in
modern ATMS systems.
6.
Q: What should be verified first when a controller clock is not synchronized with the rest of the
system?
A. Cabinet door grounding
B. Phase sequence
C. GPS or time server connection ✅
D. Detector calibration
Answer & Rationale: C – Controllers typically rely on GPS or NTP time servers; a broken
connection will result in time mismatch.
7.
Q: In TS2, what is the function of a BIU (Bus Interface Unit)?
A. Supplies power to load switches
B. Monitors conflict events
C. Converts serial data to parallel data and vice versa ✅
D. Controls pedestrian signals directly
Answer & Rationale: C – The BIU serves as a bridge between controller logic and peripheral
devices by handling serial-to-parallel data conversion.
8.
Q: What is the typical voltage level for field signal heads in a standard TS2 cabinet?
A. 12V DC
B. 5V AC
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C. 120V AC ✅
D. 24V DC
Answer & Rationale: C – Standard field signal heads operate at 120V AC for visibility and
compatibility with legacy systems.
9.
Q: Which of the following is used to isolate and protect loops from lightning-induced surges?
A. Resistor bank
B. Surge protector ✅
C. Load switch
D. Filter capacitor
Answer & Rationale: B – Surge protectors help prevent damage to loop detectors and
electronics from high-voltage spikes.
10.
Q: What documentation must be reviewed before replacing a controller with a newer model?
A. Utility plan
B. Intersection schedule
C. Bill of materials
D. Controller configuration file ✅
Answer & Rationale: D – The configuration file contains phase timing, coordination, and
detector assignments essential for setup.
11.
Q: What is the first safety step before entering a traffic signal cabinet?
A. Check for exposed wiring
B. Disable pedestrian call button
C. Ensure personal protective equipment is worn ✅
D. Unplug loop detector
Answer & Rationale: C – Wearing PPE such as insulated gloves and eye protection ensures
safety from electrical hazards.
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