IMSA Traffic Control Tech 1 QUESTIONS
& ANSWERS(GRADED A)
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
Calculating signal intervals - ANSWER Turning 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 - ANSWER Allocation of time within a single cycle for a specific movement or phase. it represent the
duration or percentage
Offset - ANSWER time 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 - ANSWER protected left-turn served prior to the complementary through movement.
most common
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
& ANSWERS(GRADED A)
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
Calculating signal intervals - ANSWER Turning 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 - ANSWER Allocation of time within a single cycle for a specific movement or phase. it represent the
duration or percentage
Offset - ANSWER time 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 - ANSWER protected left-turn served prior to the complementary through movement.
most common
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
