Download IMSA Traffic Signal Technician Level 2 Exam (2025) | Complete Study Guide with Verified Qu and more Exams Engineering in PDF only on Docsity!
IMSA Traffic Signal Technician Level 2 Exam
(2025) | Complete Study Guide with Verified
Questions & Answers
In a TS2 cabinet, how many times can the MMU experience a โPort 1 Failโ in a 24 hour period before The fault is latched? โ Answer On a 2070 MMU monitor unit, how does the field tech program allowable phases? โ AnswerRemove diode on program card for allowable phases On an MMU, is it possible to tape the reset button to prevent the traffic signal from going into flash? โ AnswerYes, it by-passes the conflict feature and will not flash
On a NEMA CMU program card, how does the signal tech program allowable phases? โ AnswerInstall copper jumpers and soldering them on the program card According to best maintenance practices, how often should CMU/MMU be tested? โ AnswerAnnually The MMU indicates a RED-FAIL fault on phase 6. Why? โ AnswerThe load switch/switch pack produces no outputs. The purpose of the controller CVM (Controller Voltage Monitor) output is to allow the CMU/MMU to Monitor the โ AnswerController health When a Technician is recertifying the CMU/MMU at an intersection, what should the technician do to have the intersection exit flash? โ AnswerReplace the CMU/MMU with a newly tested unit
When the controller timings DO NOT match the timing sheet, who should be contacted for correct Times? โ AnswerTraffic Engineer An older TS1 cabinet experiences a flash condition but the signal heads are also showing active green, yellow, and red indications. What is the MOST COMMON issue?
- AnswerThe mercury contactor is stuck in the normal position. In a Dual-Ring, 8-phase traffic signal controller, how many phases can run in each ring at the same Time? โ Answer Observations indicate that vehicles are being detected in one lane and that this is shown on the detection interface unit. However, the controller does not show any detection for that phase. This could be caused by โ AnswerImproper detection phase assignment programming in the controller
As soon as vehicles leave the detection zone of an approach that has met its minimum green time, a signal immediately goes to yellow from the green display. This could be a result of โ Answerno extension time programmed. What is one reason the phase interval may change even though there is still vehicle demand? โ Answermaximum green time has been met A signal tech is reviewing the controller logs and continually sees a cycle fault error. What does that Mean? โ AnswerThe CU has not serviced a call in two cycles while in free mode. A coordinated corridor is working well except at one intersection where a platoon of vehicles is being stopped. The MOST LIKELY problem is the โ
Why is it important for a Signal Tech to verify that the phase concurrency is the same in the controller as it is in the MMU or ATC CMU? โ AnswerThe MMU/CMU will keep the cabinet in flash until MMU mirrors what is programmed in the controller NEMA Standard TS2-2003 requires all but which of these detector faults to be reported to the Controller? โ AnswerErratic counts Observations indicate that a phase is extending to maximum green on every cycle despite no vehicles being present in the detection zone. This could be caused by โ Answera damaged loop detector for that phase A Tech is troubleshooting a cabinet where the controller is reporting a cycle fail. What does that Mean? โ AnswerThere is more time in the sum of the splits than the time programmed for the first cycle.
An intersection goes into flash every morning at exactly the same time. Which of the following is the LEAST IMPORTANT piece of data that can be retrieved from the cabinet? โ AnswerController Voltage If a Signal Tech is required to change a timing parameter in the controller, it is MOST IMPORTANT to Do which of the following? โ AnswerAlert their supervisor of the changes made A signal tech sees that the detection is working properly at the detection device, and is connected to the controller but the controller does not get the input. What could be one of the issues preventing the detection from getting to the controller? โ AnswerThe detector is not mapped in the controller correctly. Which reference contains the calculation of pedestrian timing? โ AnswerMUTCD 2009
When testing a countdown pedestrian head, how does an IMSA traffic signal field tech II determine the correct time that should be displayed in the countdown? โ AnswerThe previous pedestrian clearance time is recorded in the pedestrian head and used for the next cycle. What is the MINIMUM pedestrian clearance time for a crosswalk that is 80 feet (24 meters)? โ Answer seconds When checking the pedestrian timing in the controller, what is the proper amount of time that should be given to a pedestrian signal? โ AnswerThe clearance time is equal to the width of the intersection divided by 3.5ft/second The proper timing for a pedestrian crossing clearance phase is based on which of the following Equations? โ AnswerLength of intersection divided by 3.5 f/s (1m/s)
What is the BEST way to observe proper pedestrian push button activation? โ AnswerWalk the intersection and push each button and observe the response According to the NEC(National Electrical Code), GREEN wires in the traffic signal cabinet are only to Be used for โ Answerearth ground within the signal cabinet After connecting the phase (2) NB through movementโs loops to the vehicle detection board in the traffic signal, what should be verified? โ AnswerThat the NB through detection is placing calls on Phase (2) in the controller. Which observations for failed loop detection will indicate a field problem? โ AnswerA failed continuity test
Adding turns to a loop โ AnswerIncreases the inductance Which detection systems typically cannot be used for pedestrian detection? โ AnswerLoops What is the BEST way to determine if a loop wireโs insulation has failed? โ AnswerVisual Inspection When installing a ground rod it MUST BE installed so that the Technician can obtain an ohm reading of โ Answer25 ohm or less. Logic ground should be โ AnswerIsolated from cabinet. What is one of the QUICKEST ways to determine if a piece of electrical equipment has been burnt by a short or high voltage? โ Answerthere will be an odor that can be detected
What is a MAJOR reason for an AC line filter being installed in a cabinet? โ AnswerTo limit damaging effects of transient noise and other interference For the Emergency Vehicle Pre-Emption system, what is the BEST way for the Tech to test the operation of the system? โ AnswerDrive the corridor with a vehicle equipped with an EVP transmitter. What is the importance of track clearance time in a railroad preemption? โ AnswerIt provides the time for vehicles to exit the track area prior to the gates being lowered. What is the LAST set of steps a Technician should do after repairing any pedestrian problems? โ AnswerDocument repairs in log book and observe the traffic signal operating for several cycles. Ensure that the pedestrian and vehicle phases are operating per plan.
What is the standard used to define how traffic signal controllers and networks communicate? โ AnswerNational Transportation Communications for Intelligent Transportation systems (ITS) protocol (NTCIP). The traffic management center notifies a field tech that the communications to maple st. And 1 st street cuts in and out. The tech arrives at the intersection finding the modem is overheating and indicator lights are blank. After about twenty minutes of checking cables, the tech notices the modem is active again and cool to the touch. The TMC confirms communications are restored. The tech Checks the log book and finds this problem is a recuring issue. What should the tech do? โ AnswerReplace the modem A managed network switch is being used in the cabinet. What is needed in the IP programming of the controller to get through the switch and to the TOC? โ AnswerGateway
The pedestrian assembly (pedestrian 6) on the SW corner was damaged in a traffic accident and the tech cannot repair until the following day. What should the Tech do until they return to replace the pedestrian assembly? โ AnswerMake wiring safe. Bag opposite signal display pedestrian phase (6). Document in cabinet log book and work order system. Notify supervisor that they need a pedestrian display assembly and to schedule the installation. After doing any repairs at a traffic signal which of the following is the MOST IMPORTANT to do before leaving the intersection? โ AnswerObserve signal is operating per plans. Which of the following could cause signals at an intersection to repeatedly go into flash? โ AnswerThe MMU shows conflict on phases 2, 6, and 4 during the red interval on 2 and 6. The phase 4 field terminal is blackened and the terminal screw is loose
The Tech receives a call for a damaged signal head. When arriving on the scene, what is the FIRST thing the technician does? โ AnswerObserve the intersection. The technician arrives at an intersection where all the signals are out. What does the technician do FIRST? โ Answercheck the line service to make sure there is main power. The technician arrives at an intersection that is dark. What type of meter does the technician use The check voltage? โ AnswerMultimeter A technician received a call that a signal head was knocked down. The technician arrives on scene, repairs the problem, observes the intersection is functioning properly and completes his job duties. What is the technicianโs LAST task before leaving the intersection? โ AnswerDocument all repairs and the incident in the maintenance logs.
A technician observes two different colored signals displayed at the same time in one direction. The Tech knows the problem is LEAST LIKELY related to the โ Answerincoming power A technician arrives at the intersection and the light is on flash. What should the technician do? โ AnswerCheck the conflict monitor display and then reset it. The MOST IMPORTANT thing to do when completing work is to โ Answerdocument all changes in the maintenance logs. Faulty components should be โ Answerlabelled and marked for repair or disposal.
