- | P a g e
ISMA TRAFFIC SIGNAL TECHNICIAN II ACTUAL
EXAM VERSION A NEWEST 2025/2026
COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS|ALREADY GRADED A+
The primary purpose of the traffic signal monitor unit is to act as? - ANSWER-Guard against system malfunction
If a malfunction is present the monitoring unit will automatically put the intersection into what mode? - ANSWER-Flashing condition
An intersection will remain in flash mode until the monitor unit is? - ANSWER-Reset
The CMU and MMU checks the controller for what two things?
- ANSWER-Proper power
Timing functions
What will cause the monitor (CMU) to transfer the intersection into flash mode?(3) - ANSWER-Loss of power to the controller 1 / 4
- | P a g e
The 24 volt DC voltage of the controller is lost Time it takes to change from one indication to another is incorrect
What does each conflict monitor have that is unique for that particular intersection - ANSWER-Program card
What are short lengths of conductors on the program card called? - ANSWER-Jumpers
On the program card jumpers are installed to tell the unit "what" are considered compatible?(2) - ANSWER-Movements Channels
For NEMA type controllers positions not having jumpers are considered as? - ANSWER-Conflicts
Program cards for type 170 controllers use a "what" as a jumper to wire the positions which are considered conflicts? - ANSWER-Diode
- / 4
- | P a g e
Why is it important to periodically review the monitor cards? - ANSWER-To be sure the jumpers are assigned correctly
What is used to provide the required flash rate when the signal is in flashing operation? - ANSWER-Flasher unit
The MUTCD requires that when a signal is flashed that the light source be flashed at a rate of? - ANSWER-Not less than 50 or more than 60 times per minute
What relays are a type of relay that is capable of switching high levels of current? - ANSWER-Mercury Contactor
In a traffic signal cabinet the mercury contactor controls the 120 VAC to all of the? - ANSWER-Load switches
These devices are being replaced by many agencies due to what type of concerns? - ANSWER-Environmental
What are used in traffic signal controller cabinets that are solid- state devices that monitor a mechanical switch or button and report the call status back to the controller unit? - ANSWER- Isolators 3 / 4
- | P a g e
What are the two basic types of isolator or isolator cards? - ANSWER-AC isolators DC isolators
What are the most common isolator cards? - ANSWER-Loop detector cards
What are two other special purpose cards? - ANSWER-Video detector cards Emergency vehicle pre-emption
Load switches in the controller cabinet receive 24V DC and switch (reroute) the 120V AC to the lamps in the signal head.
This potentially reduces: (2) - ANSWER-The number of faults
induced into the controller from outside the cabinet.Electrical surges
Why do some agencies operate signals in full operation mode for a period of time, then switch to flashing mode? - ANSWER- To preserve the battery life
- / 4