Certification Examination Practice

Illinois Railroad Signal Maintainer Certification Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which federal agency primarily regulates railroad signal systems in the

United States?

A. OSHA

B. FRA

C. DOT

D. AAR

Rationale: The Federal Railroad Administration (FRA) oversees railroad

signal and train control regulations under 49 CFR Part 236.

• What is the main purpose of an automatic block signal system? 1 / 4

• Increase train speed
• Allow manual dispatching
• Maintain train separation
• Reduce power usage

Rationale: ABS systems provide block occupancy detection to maintain safe

distances between trains.

• Track circuits detect trains by sensing changes in what?
• Mechanical pressure
• Magnetic fields
• Electrical continuity
• Air displacement

Rationale: Track circuits work by detecting shunting of electrical current

when a train connects both rails.

• What is the typical voltage used in DC track circuits?

A. 240 V

B. 120 V

• Low-voltage 8–12 V

D. 48 V

Rationale: Traditional DC track circuits operate with low-voltage supplies

for safety and reliability.

• What happens when a track circuit becomes shunted? 2 / 4

• Signal clears
• Relay energizes
• Relay drops
• Power increases

Rationale: A shunted track circuit causes the relay to de-energize,

indicating track occupancy.

• What is the most common cause of false occupancy in track circuits?
• Overvoltage
• Poor ballast conditions
• Hot weather
• Signal maintainer error

Rationale: High moisture or poor ballast reduces insulation and causes

unintended current leakage.

7. A vital relay is designed so that it will:

• Fail energized
• Fail safe
• Work in both AC and DC
• Accept remote programming

Rationale: Vital relays are engineered to default to the safest condition—

de-energized—if failure occurs.

• Which tool is typically used to check track circuit voltage? 3 / 4

• Clamp-on ammeter
• Relay test set
• Multimeter
• Torque wrench

Rationale: A multimeter accurately measures voltage, current, and

continuity in signal circuits.

• What is the function of an approach signal?
• Allows trains into yards
• Warns the engineer of an upcoming stop
• Marks end of the block
• Indicates switch alignment

Rationale: Approach signals notify the engineer that the next signal may

require a stop.

• Which conductor size is most commonly used in signal control circuits?

A. 10 AWG

B. 20 AWG

C. 14 AWG

D. 6 AWG

Rationale: 14 AWG wire is standard for control and relay circuits in signal

systems.

• What is the primary purpose of insulated joints?
• / 4