#1
Which of the following formulas is used to calculate the average speed?
Average speed = Distance / Time
ExplanationAverage speed is calculated by dividing the distance traveled by the time taken.
#2
What is the 85th percentile speed?
The speed at which 85% of the vehicles are traveling at or below
Explanation85th percentile speed represents the point where 85% of vehicles have equal or lower speeds.
#3
What is the formula to calculate the 85th percentile speed?
85th percentile speed = (Total number of vehicles × 0.85)th vehicle's speed
ExplanationThe 85th percentile speed is determined by sorting all speeds, then finding the speed at the 85th percentage.
#4
In a study, the 85th percentile speed is found to be 60 mph. What does this mean?
85% of the vehicles are traveling at or below 60 mph
ExplanationThe 85th percentile speed being 60 mph indicates that 85% of vehicles have speeds of 60 mph or lower.
#5
Which of the following factors affect the 85th percentile speed?
All of the above
ExplanationVarious factors, including road conditions, driver behavior, and speed limits, collectively affect the 85th percentile speed.
#6
In traffic studies, what does the term 'speed dispersion' refer to?
The variation in speeds among vehicles
ExplanationSpeed dispersion in traffic studies refers to the range of speeds observed among different vehicles.
#7
What is the purpose of using speed percentiles in traffic analysis?
To understand the distribution of speeds
ExplanationSpeed percentiles are used in traffic analysis to gain insights into how speeds are distributed among vehicles.
#8
Which speed percentile is often used as a benchmark for setting speed limits?
85th percentile
ExplanationThe 85th percentile speed is commonly used as a benchmark for determining appropriate speed limits.
#9
What is the 15th percentile speed?
The speed at which 15% of the vehicles are traveling at or below
Explanation15th percentile speed is the point where 15% of vehicles have speeds equal to or lower than this value.
#10
What is the formula to calculate the coefficient of variation of speeds?
Coefficient of variation = Standard deviation of speeds / Mean speed
ExplanationThe coefficient of variation is computed by dividing the standard deviation of speeds by the mean speed.
#11
How does the coefficient of variation value indicate speed distribution?
Higher coefficient of variation indicates less uniform speed distribution
ExplanationA higher coefficient of variation suggests greater variability in speed, indicating a less uniform speed distribution.
#12
What does it signify if the coefficient of variation value is close to zero?
Uniform speed distribution
ExplanationA coefficient of variation close to zero indicates a uniform speed distribution with minimal variation among speeds.
#13
In traffic engineering, what is the 'trailing speed'?
The speed at the rear end of a traffic queue
ExplanationTrailing speed in traffic engineering refers to the speed observed at the rear end of a traffic queue.
#14
Which parameter is NOT used in determining the 85th percentile speed?
Speed of the 85th percentile vehicle
ExplanationThe speed of the 85th percentile vehicle is not directly used in determining the 85th percentile speed; it is based on the rank order of all speeds.