Questions and Answers 100% Correct
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
Lag Left-Turns - ANSWER - Protected left turn served after the complementary through movement. most
used in coordinated systems with closely spaced lag left turn intersections such as diamond interchanges
Lead-Lag Left Turns - ANSWER - leading and lagging left turn are provided on opposing approached of
the same street
BUS/BIU - ANSWER - central control unit, allowing communication between controller and detectors,
signal heads, communication equipment
Traffic Detectors - ANSWER - inductive loop detectors or video cameras , providing input about the
presence and movement of vehicles or pedestrians
Communication Equipment - ANSWER - communicate with central traffic management system such as
remote monitoring systems or emergency vehicle preemption systems
Split Phase Left-Turns - ANSWER - Volume of traffic is heavier on one side of street causing the green
arrows to end at different times
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