250+ TOP MCQs on Spot Speed Study and Answers

Traffic Engineering Multiple Choice Questions on “Spot Speed Study”.

1. Why are Spot speed studies conducted?
a) To record the distribution of vehicle speeds
b) To record the distribution of time taken to reach a destination
c) To design signals
d) To determine design speed
Answer: a
Clarification: Spot speed studies are conducted to document the distribution of vehicle speeds as they pass a cross-section of the highway. Spot speed is the instantaneous speed of a vehicle at a location.

2. On a freeway, spot speed studies are not conducted if the traffic volumes exceed _____
a) 700-1000 veh/hr/ln
b) 500-600 veh/hr/ln
c) 750-1000 veh/hr/ln
d) 100-200 veh/hr/ln
Answer: c
Clarification: On a freeway, spot speed studies are not conducted if the traffic volumes exceed 750-1000 veh/hr/ln. On an uninterrupted flow facility, the spot speed studies are not conducted if the traffic volumes exceed 500 veh/hr/ln.

3. The mean speed of all the vehicles crossing a location is known as ________
a) Standard deviation
b) Median
c) Time mean speed
d) Pace
Answer: c
Clarification: The mean speed of all the vehicles crossing a location is known as Time mean speed during the period of study. Time mean speed is the mean of instantaneous speeds. It helps to decide the distribution of speeds of vehicles.

4. Which of the following is a method to measure spot speed?
a) Long Base method
b) Aerial Photography
c) Inductive loop detector
d) Weigh In Motion (WIM) sensor
Answer: a
Clarification: Long Base method is a method to measure spot speed. In the Long Base method, vehicles are timed over a long distance. The second method to measure spot speed is Short Base method. In the Short Base method, vehicles are timed over a short distance of about 2m.

5. What is the disadvantage of Direct Timing procedure?
a) Parallax effect
b) Uneconomical
c) Complicated
d) Inaccurate results
Answer: a
Clarification: The disadvantage of Direct Timing procedure is the Parallax effect. Direct Timing procedure is the simplest procedure for Long base method. The reaction time of the observers is also a disadvantage here.

6. Which of the following is not a procedure of Long base method?
a) Direct Timing procedure
b) Enoscope
c) Pressure contact tubes
d) Radar speed meters
Answer: d
Clarification: Radar speed meters is not a procedure of Long base method. Direct Timing procedure, Enoscope, and Pressure contact tubes are the procedure of Long base method.

7. Which of the following is a disadvantage of Pressure contact tubes?
a) Low initial cost
b) Simple to install
c) Easy maintenance
d) Tubes are visible which affects the driver’s behaviour
Answer: d
Clarification: The disadvantage of Pressure contact tubes is that the tubes are visible which affects the driver’s behaviour. The rest of the options are the advantages of Pressure syntactic tubes.

8. Which of the following is an advantage of Enoscope?
a) Tubes are visible which affects the driver’s behaviour
b) Parallax effect
c) Inaccurate results
d) Eliminates Parallax error
Answer: d
Clarification: The advantage of Enoscope is that it eliminates Parallax error. Enoscope is also inexpensive, simple, and easily installable. Enoscope is also called Mirror box. It is an L- shaped box with a mirror set at 45 degrees to the arms of the instrument.

9. Which of the following instrument works on the Doppler principle?
a) Enoscope
b) Radar speed meter
c) Pressure contact tubes
d) Time lapse camera
Answer: b
Clarification: Radar speed meter is the instrument that works on the Doppler principle. Radar speed meters directly measure speed. It is installed near the edge of the carriageway at a height of 1m.

10. The average difference between observed speeds and time mean speed is _____
a) 85^th percentile speed
b) Median
c) Standard deviation
d) Pace
Answer: c
Clarification: The average difference between observed speeds and time mean speed is Standard deviation. 85^th percentile speed is the speed beneath which 85% of the vehicles are driven. Median is the speed that equally divides the spot speed distribution.