# 250+ TOP MCQs on Introduction to Highway Capacity and Answers

Traffic Engineering Multiple Choice Questions on “Introduction to Highway Capacity”.

1. What is the definition of Highway Capacity?
a) The minimum traffic flow that can be accommodated in a highway facility in a given time period under existing roadway and control conditions
b) The maximum traffic flow that can be accommodated in a highway facility in the future
c) The minimum traffic flow that can be accommodated in a highway facility according to data from the previous year
d) The maximum traffic flow that can be accommodated in a highway facility in a given time period under existing roadway and control conditions
Answer: d
Clarification: Highway Capacity is the maximum traffic flow that can be contained in a highway facility in a given time period under existing roadway and control conditions. It is the maximum flow under prevailing conditions of road and traffic control systems.

2. How many types of highway capacity was defined by Highway Capacity Manual (1950)?
a) 2
b) 5
c) 3
d) 4
Answer: c
Clarification: There are 3 types of highway capacity defined by Highway Capacity Manual (1950). They are basic capacity, possible capacity, and practical capacity. Highway Capacity Manual was introduced by O.K Norman.

3. Which of the following capacity is considered as design capacity?
a) Basic capacity
b) Possible capacity
c) Practical capacity
d) Traffic capacity
Answer: c
Clarification: Practical capacity is considered as design capacity. Practical capacity is the highest number of vehicles that can cross a given point in the roadway in an hour when the traffic density does not cause any risk or unwanted delay.

4. Which of the following parameter is not dependent on highway capacity?
a) Class of highway
b) Lane width
c) Number of lanes
d) Gauge width
Answer: d
Clarification: Gauge width is the parameter that is not dependent on highway capacity. Class of highway, lane width, number of lanes, and intersections are the parameters dependent on highway capacity. Development of traffic management measures, geometric elements, and traffic control devices can also be achieved with the aid of studies on highway capacity.

5. What is the capacity value for urban roads as per IRC for one-way traffic flow with two lanes?
a) 1500 PCU/hr
b) 2400 PCU/hr
c) 3600 PCU/hr
d) 4000 PCU/hr
Answer: b
Clarification: The capacity value for urban roads as per IRC for one-way traffic flow with two-lane is 2400 PCU/hr. It is 1500 PCU/hr for two-way two-lane traffic flow and 3600 PCU/hr for one-way three-lane traffic flow.

6. Which of the following is not a factor affecting traffic capacity?
a) Lane width
b) Lateral clearance
c) Gradient
d) Traffic control devices
Answer: c
Clarification: Traffic control devices is not a factor affecting traffic capacity. Roadway conditions such as lane width, lateral clearance, gradient, and shoulders affect traffic capacity. Traffic conditions such as number of traffic lanes, driver characteristics, types of vehicles on the road also affect traffic capacity.

7. Highway capacity is independent of _____
a) demand
b) lane width
c) geometric design
d) traffic conditions
Answer: a
Clarification: Highway capacity is independent of demand. Capacity is the number of vehicles that the road can accommodate in its existing condition. It is independent of the number of vehicles demanding service.

8. Capacity is a probabilistic measure.
a) True
b) False
Answer: a
Clarification: “Capacity is a probabilistic measure” is a correct statement. It varies with respect to location and time. It is generally obtained through field observations.

9. What is maximum flow rate?
a) Worst 15 minutes of the peak hours
b) Worst 10 minutes of peak hours
c) Worst 30 minutes of the peak hours
d) Worst 5 minutes of the peak hours
Answer: a
Clarification: Maximum flow rate is the worst 15 minutes of the peak hours. Capacity is the maximum flow rate that the road facilities can bear in prevailing condition.

10. Capacity is measured as a reasonably expected value and not the maximum flow rate observed in the facility. Why?
a) Because capacity at a given location varies from day to day
b) Because capacity at a given location doesn’t vary
c) Because capacity at a given location varies from year to year
d) Because capacity at a given location decreases simultaneously
Answer: a
Clarification: Capacity is measured as a reasonably expected value and not the maximum flow rate observed in the facility. This is because capacity at a given location varies from day to day due to various factors like local driving habits.