High-Traffic Areas - answerHigh-volume streets, such as arterials. Typically wide and
have multiple lanes of travel.
Low-Traffic Areas - answerLow-volume streets such as local streets or collector streets.
Typically narrow and have single lanes of travel.
Insulated Hand Tools - answerTools with insulated handles, designed to protect from
electric shock when working with live electricity.
Insulated Mats/Blankets - answerSafe place to stand when working on electric systrems
Circuit Breaker Finders - answerTool that helps locate the appropriate circuit breaker or
fuse that controls the electrical supply to the area.
Conductors - answerMaterials that conduct electricity
Ex. Most metals
Insulators - answerMaterials that do not conduct electricity
EX. plastic, rubber, glass, ceramic
Understanding electricity - answerElectricity 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 - answerE = I x R
E = Voltage(Electromotive Force) (Volts)
I = Current(Intensity) (Amps)
R = Resistance (Ohms)
120 VAC/ 24 VDC - answerTypical voltages used in traffic signal circuits
Alternating Current - answerThe 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 - answerelectrons flow in one direction
5, 12, 24 Volts usually
, EX. Batteries, power supplies
Bonding and grounding - answerJoining metallic parts and using them to provide an
electrically conductive path to the ground
Phases - answerThrough 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 - answerphases 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 - answeridentifies 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 - answerSeparates opposing phases to avoid conflicting movements at the same
time. Also helps in rings relationship
Protected Phases - answerProvide exclusive right-of-way to a specific movement,
allowing passage with no conflicting traffic
Permissive Phases - answerAllow movement to proceed with caution when there is a
gap in conflicting traffic. Usually yielding or giving right of way to crossing traffic
Calculating signal intervals - answerTurning movement counts - data on traffic volume
Signal phasing- data on terrain
Minimum green time- time to clear intersection
Pedestrian clear time
Yellow & All-Red Intervals
Coordination & Optimization
Split - answerAllocation of time within a single cycle for a specific movement or phase. it
represent the duration or percentage
Offset - answertime difference between the initiation of signal phases or intersections
along a corridor. Effective offset can help reduce stops, improve travel times, enhance
fuel efficiency
Lead Left-Turns - answerprotected left-turn served prior to the complementary through
movement. most common
Lag Left-Turns - answerProtected left turn served after the complementary through
movement. most used in coordinated systems with closely spaced lag left turn
intersections such as diamond interchanges
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