Traffic Signal & Signage Installation Flashcards

A mast arm traffic signal pole is being installed. What factor primarily determines the required pole height?

Answer: The number of lanes and required horizontal clearance for signal heads

Mast arm height is determined by the number of lanes to span and the required vertical and horizontal clearances for mounted signal heads.

What does 'intergreen' refer to in traffic signal terminology?

Answer: The yellow change interval plus the all-red clearance interval between phases

Intergreen is the combined yellow change and all-red clearance interval that separates conflicting traffic movements.

When should retroreflective sign sheeting be inspected for replacement on KDOT facilities?

Answer: Based on a scheduled maintenance program considering sheeting age and measured retroreflectivity

MUTCD requires agencies to use either an assessment or management method to ensure sign retroreflectivity is maintained above minimum levels.

A STOP sign must be installed at what height on an urban roadway with sidewalks?

Answer: 7 feet minimum to bottom of sign

MUTCD requires a minimum mounting height of 7 feet from the bottom of the sign to the sidewalk level in pedestrian areas.

What is the purpose of a detector loop in a traffic signal system?

Answer: To detect vehicle presence or passage and send actuation data to the controller

Inductive loop detectors sense the presence or passage of vehicles by detecting changes in inductance, sending this data to the signal controller for actuation.

When installing overhead sign structures on KDOT highways, which specification primarily governs the structural design?

Answer: AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals

AASHTO's Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals governs the structural design of overhead sign supports.

What is a 'flashing beacon' used for in traffic control?

Answer: To provide additional emphasis or warning at specific locations such as school zones or stop signs

Flashing beacons supplement other signs or signals to draw driver attention to important locations like school crossings or unexpected stop conditions.