Traffic Engineering Multiple Choice Questions on “Presentation of Spot Speed Data”.
1. Which of the following is not a way by which spot speed data is presented?
a) Average speed of vehicles
b) Modal average
c) Cumulative speed of vehicles
d) Variation charts
Answer: d
Clarification: Variation charts is not a way by which spot speed data is presented. Variation charts are used for the presentation of traffic volume data. The Average speed of vehicles, modal average, and cumulative speed of vehicles are the way by which spot speed data is presented.
2. Which of the following way of presentation of spot speed data is a mathematical analysis?
a) Average speed of vehicles
b) Modal average
c) Cumulative speed of vehicles
d) Variation charts
Answer: a
Clarification: The average speed of vehicles is the way of presentation of spot speed data which has a mathematical approach. In this analysis, arithmetic speed is taken as average speed.
3. The speed corresponding to the summit of the frequency distribution curve of spot speeds is _______
a) Peak speed
b) Ruling speed
c) Modal speed
d) Mean speed
Answer: c
Clarification: The speed corresponding to the summit of the frequency distribution curve of spot speeds is Modal speed. It is the speed at which largest number of vehicles travel.
4. What is the use of a cumulative speed distribution curve?
a) To determine the speed above or below which certain percentages of vehicles are moving
b) To determine the traffic volume
c) To determine the modal speed
d) To determine the PCU
Answer: a
Clarification: Cumulative speed distribution curve is used to determine the speed above or below which certain percentages of vehicles are moving. This graph has the mean values of each speed group on the x-axis and the cumulative percentage on the y-axis.
5. Which of the following is considered to be the safe speed limit?
a) 98 percentile speed
b) 85 percentile speed
c) 50 percentile speed
d) 10 percentile speed
Answer: b
Clarification: 85 percentile speed is considered to be the safe speed limit. 85 percentile speed is the speed beneath which 85% of the vehicles are travelling at a point (15% of the vehicles exceed this speed at the point).
6. Which of the following is considered to be the minimum speed limit on a highway?
a) 98 percentile speed
b) 85 percentile speed
c) 15 percentile speed
d) 10 percentile speed
Answer: c
Clarification: 15 percentile speed is considered to be the minimum speed limit on a highway. Speed less than this is generally prohibited since it leads to congestion and accidents.
7. 98 percentile speed is _____
a) design speed
b) safe speed
c) minimum speed
d) median speed
Answer: a
Clarification: 98 percentile speed is design speed. It is the speed that is used for geometric design purposes. Median speed is the 50 percentile speed, safe speed is 85 percentile speed and the minimum speed is 15 percentile speed.