R7 Flashcards
What is the purpose of a traffic signal system?
Encourage flow of vehicles and pedestrians through an intersection in a safe and timely manner
What are the three basic subsystems?
Signal light and housing
Supporting arms/poles/underground support
Electrical controllers
What are the electrical controllers?
Can be thought of as brain of the system.
Accepts all input data and performs logic based programming and directs the traffic lights accordingly.
What are the 5 types of signal system?
Actuated signalized intersections
Warning flashers/beacons
Pedestrian signals
Fire station signals
Moveable bridge and warning systems
How does an induction loop traffic sensor work?
It uses the low reluctance of a vehicle in the magnetic field to detect the vehicle.
What are the two most used traffic control systems?
Local time based
Dynamic/Adaptive
Local time based traffic control system
Programmed, no input to change output, once programmed that’s how it is.
Dynamic/adaptive traffic control system
Responds to real time data and can be linked to other controllers to work together.
What does a Conflict Monitor Unit do?
Ensures fail-safe operation by monitoring the outputs
What colour should warning flashers be?
Amber or red
What word is commonly used to describe a signal light head that contains red, amber, and green lights?
Stack
If a pole is to be erected in the corner of an intersection, what must it be mounted on?
Engineered underground concrete support
What may be required at controllers whose area is prone to power outages?
Battery back up
