IMSA Traffic Control Tech 1
Comprehensive Questions
(Frequently Most Tested) and
Verified Answers
High-Traffic Areas - Answer: High-volume streets, such as arterials. Typically wide and have multiple
lanes of travel.
Low-Traffic Areas - Answer: Low-volume streets such as local streets or collector streets. Typically
narrow and have single lanes of travel.
Insulated Hand Tools - Answer: Tools with insulated handles, designed to protect from electric shock
when working with live electricity.
Insulated Mats/Blankets - Answer: Safe place to stand when working on electric systrems
Circuit Breaker Finders - Answer: Tool that helps locate the appropriate circuit breaker or fuse that
controls the electrical supply to the area.
Conductors - Answer: Materials that conduct electricity
Ex. Most metals
Insulators - Answer: Materials that do not conduct electricity
EX. plastic, rubber, glass, ceramic
Understanding electricity - Answer: Electricity is similar as water flowing through pipes
Voltage is like water pressure.
Current is like amount of water.
Resistance is like the size of the pipe.
, Ohm's Law - Answer: E = I x R
E = Voltage(Electromotive Force) (Volts)
I = Current(Intensity) (Amps)
R = Resistance (Ohms)
120 VAC/ 24 VDC - Answer: Typical voltages used in traffic signal circuits
Alternating Current - Answer: The electrons flow in a switching direction going forward and backwards.
In a power grid usually 120 Volts at 60 cycles per second(Hertz)
EX.Powers homes, businesses, factories
Direct Current - Answer: electrons flow in one direction
5, 12, 24 Volts usually
EX. Batteries, power supplies
Bonding and grounding - Answer: Joining metallic parts and using them to provide an electrically
conductive path to the ground
Phases - Answer: Through phases are typically even numbered and left turn phases are odd numbered.
Phases 1- 2- 5- 6 are the main street, while 3 -4 - 7 -8 are the side street
Concurrent group - Answer: phases that are grouped on the same street. phases usually turn on with the
the others in their group. divided by barrier, e.g main street/ side street
Ring - Answer: identifies phases that may operate one after another. organizing conflicting phases such
as a left turn not being on while through is on the opposite way.
Barrier - Answer: Separates opposing phases to avoid conflicting movements at the same time. Also
helps in rings relationship
Comprehensive Questions
(Frequently Most Tested) and
Verified Answers
High-Traffic Areas - Answer: High-volume streets, such as arterials. Typically wide and have multiple
lanes of travel.
Low-Traffic Areas - Answer: Low-volume streets such as local streets or collector streets. Typically
narrow and have single lanes of travel.
Insulated Hand Tools - Answer: Tools with insulated handles, designed to protect from electric shock
when working with live electricity.
Insulated Mats/Blankets - Answer: Safe place to stand when working on electric systrems
Circuit Breaker Finders - Answer: Tool that helps locate the appropriate circuit breaker or fuse that
controls the electrical supply to the area.
Conductors - Answer: Materials that conduct electricity
Ex. Most metals
Insulators - Answer: Materials that do not conduct electricity
EX. plastic, rubber, glass, ceramic
Understanding electricity - Answer: Electricity is similar as water flowing through pipes
Voltage is like water pressure.
Current is like amount of water.
Resistance is like the size of the pipe.
, Ohm's Law - Answer: E = I x R
E = Voltage(Electromotive Force) (Volts)
I = Current(Intensity) (Amps)
R = Resistance (Ohms)
120 VAC/ 24 VDC - Answer: Typical voltages used in traffic signal circuits
Alternating Current - Answer: The electrons flow in a switching direction going forward and backwards.
In a power grid usually 120 Volts at 60 cycles per second(Hertz)
EX.Powers homes, businesses, factories
Direct Current - Answer: electrons flow in one direction
5, 12, 24 Volts usually
EX. Batteries, power supplies
Bonding and grounding - Answer: Joining metallic parts and using them to provide an electrically
conductive path to the ground
Phases - Answer: Through phases are typically even numbered and left turn phases are odd numbered.
Phases 1- 2- 5- 6 are the main street, while 3 -4 - 7 -8 are the side street
Concurrent group - Answer: phases that are grouped on the same street. phases usually turn on with the
the others in their group. divided by barrier, e.g main street/ side street
Ring - Answer: identifies phases that may operate one after another. organizing conflicting phases such
as a left turn not being on while through is on the opposite way.
Barrier - Answer: Separates opposing phases to avoid conflicting movements at the same time. Also
helps in rings relationship
