Traffic Engineering Interview Questions and Answers on “Traffic Engineering Studies – 2”.
1. What was the first permanent detector used?
a) Inductive loop
b) Pressure plate
c) Magnetic detector
d) Magnetometer
Answer: b
Clarification: The first permanent detector used was Pressure plate. Two plates separated by rubber spring is connected to low voltage power source. When a vehicle moves over it, the two plates comes together completing the circuit and creating an electric pulse.
2. What is the principle used by the inductive loop?
a) Induction
b) Electromagnetic field
c) Doppler effect
d) Scattering
Answer: b
Clarification: The principle used by the inductive loop is Electromagnetic field. When a vehicle enters the field of loop, inductance properties of loop decreases and the presence of a vehicle is recorded.
3. What is the standard loop detector size?
a) 12ft X 12ft
b) 10ft X 10ft
c) 6ft X 6ft
d) 5ft X 5ft
Answer: c
Clarification: The standard loop detector size is 6ft X 6ft. And it covers only one lane. Longer loops are also available from size ranging from 6ft X 40ft to 6ft X 80ft.
4. Inductive loop directly measures ________
a) Speed of vehicles
b) Delay time
c) Passage and presence of vehicles
d) Travel time from one location to another
Answer: c
Clarification: Inductive loop measure’s passage and presence of vehicles. Speed and density of vehicles can be calibrated from algorithms.
5. What are the two types of magnetic detector?
a) Magnetometer and magnetic sensor
b) Speed detector and magnetic sensor
a) Magnetometer and speed detector
b) Density detector and speed detector
Answer: a
Clarification: The two types of magnetic detector are magnetometer and a magnetic sensor. Magnetic detectors are a type of permanent detector.
6. Which magnetic detector can measure both passage and presence of vehicles?
a) Magnetometer
b) Magnetic sensor
c) Magnetometer and Magnetic sensor
d) Speedometer
Answer: a
Clarification: Magnetic detector which can measure both passage and presence of vehicles is Magnetometer. Magnetic sensor can detect only passage of vehicles.
7. What is the principle upon which the magnetic detector is based on?
a) Doppler effect
b) Electromagnetic field
c) Moving metal disturbs earth’s magnetic field
d) Charles law
Answer: c
Clarification: The principle that magnetic detector is based on is that moving metal i.e. vehicles disturbs earth’s magnetic field. This disturbance is detected and counted.
8. Magnetic detectors are placed over roadway.
a) True
b) False
Answer: b
Clarification: Magnetic detectors are placed under the roadway. They are also placed under the sub-base. They are used to estimate movement and presence of vehicles. Commonly used magnetic detectors are Magnetometer and Magnetic sensor.
9. What is the use of second wire loop on the Magnetometer?
a) To detect passage
b) To detect presence
c) To detect speed
d) To detect density
Answer: b
Clarification: The use of the second wire loop on the Magnetometer is to detect presence. Magnetic sensor has limited application since they are passage only magnetic detectors.
10. Aerial photography uses which basic platform?
a) A stationary elevated vantage point
b) Satellite
c) Skydiving
d) Hot air balloon
Answer: a
Clarification: Aerial photography uses three basic platforms. They are i) A stationary elevated vantage point, ii) fixed wing aircraft and iii) helicopters.
11. Which process captures individual vehicle traces through the photographed segment?
a) Aerial photography
b) Digitizing
c) Operating
d) Tracing
Answer: b
Clarification: The process which captures individual vehicle traces through the photographed segment is called digitizing. This process needs two or more fixed objects whose coordinates are known in every frame captured.
12. Which is the most desirable platform for aerial photography?
a) Elevated vantage point
b) Fixed wing aircraft
c) Helicopters
d) Satellite
Answer: a
Clarification: Elevated vantage point is the most desirable platform for aerial photography because throughout the study the camera is fixed. Aircraft and helicopters need to move and hover around which makes the camera non-stationary, which is not desirable for surveying.
13. Which is the most suitable study for information on trip purpose?
a) Traffic counting
b) Interview study
c) Parking counts
d) Tracking
Answer: b
Clarification: The most suitable study for information on trip purpose is Interview study. Some of the interview studies are Roadside interview, Comprehensive home interview, and destination based interview.
14. In which of the following interview study traffic is disrupted?
a) Roadside interview
b) Comprehensive home interview
c) Destination-based interview
d) Parking survey
Answer: a
Clarification: In Roadside interview study, traffic is disrupted. The drivers are stopped to ask questions, in this survey. Therefore they are usually conducted near traffic signals so that traffic is not interrupted. Comprehensive home interview and Destination-based interview doesn’t disrupt traffic movement.
Traffic Engineering for Interviews,