IMSA Traffic Signal Technician I EXAM
STUDY GUIDE 2026/2027 ACCURATE
QUESTIONS WITH CORRECT DETAILED ANSWER
|| 100% GUARANTEED PASS
<RECENT VERSION>
1. IMSA - ANSWER ✔ The International Municipal Signal Association
(IMSA) is the
oldest known association of its kind in the world. The
organization originated in 1896 and counts Thomas A. Edison
and the Edison Electric Company among its esteemed
members. Today, IMSA certifies tens of thousands of
technicians and stands as the most regarded name in public
safety.
2. First recorded attempt of regulating traffic flow with a mechanical signal?
(where, when, who, how) - ANSWER ✔ Where: London, England
When: 1868
Who: J.P. Knight, railway engineer
How: Featured rotating arms with symbols indicating stop and go
3. Pivotal milestone of traffic signal? (Where, when, who, how) - ANSWER ✔
Where: Salt Lake City
When: 1912
Who: Lester Wire, Salt Lake City policeman
How: First electric traffic signal with red and green lights and buzzer to
guide vehicles
,4. Significant breakthrough of traffic signal (Where, when, who, how) -
ANSWER ✔ Where: Detroit
When: 1920
Who: William Potts, Detroit police officer
How: Introduced concept of amber (yellow) light, adding a crucial buffer
5. Garrett Augustus Morgan - ANSWER ✔ African American inventor,
invented three position signal to add a warning position (1923, patented).
Also invented a gas mask to protect firefighters
6. NEMA - ANSWER ✔ National Electrical Manufacturers Association -
Founded in 1926, neutral forum of members made up of business leaders,
electrical experts, engineers, scientists, technicians. ANSI-accredited
Standards Developing Organization
7. _____________ are needed to be adjusted to eliminate any detection
irregularities due to interference problems with detectors? - ANSWER ✔
frequency and sensitivity
8. What types of loops are used for traffic count purposes and for coordinating
the traffic signal system based upon real-time traffic volumes? - ANSWER
✔ system
9. What is a disadvantage of video imaging detection systems? - ANSWER ✔
maintenance requires advanced technical training
10.Which advanced traffic control environment can distributed architecture
NOT provide the necessary performance? - ANSWER ✔ traffic coordinated
control
,11.What is the common term for a cable that transmits data between controllers
and on-street masters/central computers? - ANSWER ✔ hardwire
12.Define POTS - ANSWER ✔ plain old telephone service
13.Which of the following is NOT a dip switch setting? - ANSWER ✔ cycle
length
14.What's true about fiber optic cables? - ANSWER ✔ -can transmit data faster
than older copper cables
-data can be sent sent in both directions are the same time
- can be utilized for closed circuit television feeds
15.What is an advantage of single mode fiber optic cable over multi-mode fiber
optic cable? - ANSWER ✔ has a higher transmission rate than multi-mode
fiber
16.What converts electronic data to and from laser light for transmission? -
ANSWER ✔ fiber optic modems
17.What is ODTR - ANSWER ✔ one trial driven reflectometer
18.Limited channel availability, requires line of sight path between antennae,
possible interference due to weather is a (disadvantage or advantage) of
microwave communications system - ANSWER ✔ disadvantage
19.Why is maintenance documentation so important? - ANSWER ✔ - to
prevent litigation
, -historical database
- planning for spare parts and replacement equipment
20.UPS - ANSWER ✔ Uninterruptable power supply aka battery backup
21.Maintenance switch panel - ANSWER ✔ Specialized control panel inside
cabinet door (coordinated, flash, etc)
22.What supports signal heads on span wire? - ANSWER ✔ Messenger wire
23.What cabinet device acts as an interface device between the controller and
the field terminals? - ANSWER ✔ Load switch
24.What cabinet device switches the traffic signals between a flash state and
normal operation? - ANSWER ✔ Flash Transfer Relay
25.What cabinet device facilitates communications between the field terminals,
the detection devices and the MMU? - ANSWER ✔ b) Bus Interface Unit
26.The MUTCD states that the flashing output on a flasher must be _____ per
minute? - ANSWER ✔ b) 50-60
27.What unit is described as the brain of the traffic signal system? - ANSWER
✔ c) Controller
28.It is recommended that a CMU/MMU get tested & recertified ________? -
ANSWER ✔ Annually
STUDY GUIDE 2026/2027 ACCURATE
QUESTIONS WITH CORRECT DETAILED ANSWER
|| 100% GUARANTEED PASS
<RECENT VERSION>
1. IMSA - ANSWER ✔ The International Municipal Signal Association
(IMSA) is the
oldest known association of its kind in the world. The
organization originated in 1896 and counts Thomas A. Edison
and the Edison Electric Company among its esteemed
members. Today, IMSA certifies tens of thousands of
technicians and stands as the most regarded name in public
safety.
2. First recorded attempt of regulating traffic flow with a mechanical signal?
(where, when, who, how) - ANSWER ✔ Where: London, England
When: 1868
Who: J.P. Knight, railway engineer
How: Featured rotating arms with symbols indicating stop and go
3. Pivotal milestone of traffic signal? (Where, when, who, how) - ANSWER ✔
Where: Salt Lake City
When: 1912
Who: Lester Wire, Salt Lake City policeman
How: First electric traffic signal with red and green lights and buzzer to
guide vehicles
,4. Significant breakthrough of traffic signal (Where, when, who, how) -
ANSWER ✔ Where: Detroit
When: 1920
Who: William Potts, Detroit police officer
How: Introduced concept of amber (yellow) light, adding a crucial buffer
5. Garrett Augustus Morgan - ANSWER ✔ African American inventor,
invented three position signal to add a warning position (1923, patented).
Also invented a gas mask to protect firefighters
6. NEMA - ANSWER ✔ National Electrical Manufacturers Association -
Founded in 1926, neutral forum of members made up of business leaders,
electrical experts, engineers, scientists, technicians. ANSI-accredited
Standards Developing Organization
7. _____________ are needed to be adjusted to eliminate any detection
irregularities due to interference problems with detectors? - ANSWER ✔
frequency and sensitivity
8. What types of loops are used for traffic count purposes and for coordinating
the traffic signal system based upon real-time traffic volumes? - ANSWER
✔ system
9. What is a disadvantage of video imaging detection systems? - ANSWER ✔
maintenance requires advanced technical training
10.Which advanced traffic control environment can distributed architecture
NOT provide the necessary performance? - ANSWER ✔ traffic coordinated
control
,11.What is the common term for a cable that transmits data between controllers
and on-street masters/central computers? - ANSWER ✔ hardwire
12.Define POTS - ANSWER ✔ plain old telephone service
13.Which of the following is NOT a dip switch setting? - ANSWER ✔ cycle
length
14.What's true about fiber optic cables? - ANSWER ✔ -can transmit data faster
than older copper cables
-data can be sent sent in both directions are the same time
- can be utilized for closed circuit television feeds
15.What is an advantage of single mode fiber optic cable over multi-mode fiber
optic cable? - ANSWER ✔ has a higher transmission rate than multi-mode
fiber
16.What converts electronic data to and from laser light for transmission? -
ANSWER ✔ fiber optic modems
17.What is ODTR - ANSWER ✔ one trial driven reflectometer
18.Limited channel availability, requires line of sight path between antennae,
possible interference due to weather is a (disadvantage or advantage) of
microwave communications system - ANSWER ✔ disadvantage
19.Why is maintenance documentation so important? - ANSWER ✔ - to
prevent litigation
, -historical database
- planning for spare parts and replacement equipment
20.UPS - ANSWER ✔ Uninterruptable power supply aka battery backup
21.Maintenance switch panel - ANSWER ✔ Specialized control panel inside
cabinet door (coordinated, flash, etc)
22.What supports signal heads on span wire? - ANSWER ✔ Messenger wire
23.What cabinet device acts as an interface device between the controller and
the field terminals? - ANSWER ✔ Load switch
24.What cabinet device switches the traffic signals between a flash state and
normal operation? - ANSWER ✔ Flash Transfer Relay
25.What cabinet device facilitates communications between the field terminals,
the detection devices and the MMU? - ANSWER ✔ b) Bus Interface Unit
26.The MUTCD states that the flashing output on a flasher must be _____ per
minute? - ANSWER ✔ b) 50-60
27.What unit is described as the brain of the traffic signal system? - ANSWER
✔ c) Controller
28.It is recommended that a CMU/MMU get tested & recertified ________? -
ANSWER ✔ Annually
