Highway Engineering Multiple Choice Questions on “Design of Traffic Intersections”.
1. Which of the following is not an intersection at grade?
a) Un-channelized
b) Channelized
c) Rotary
d) Different level intersections
Answer: d
Clarification: The intersection at grade include un channelized, channelized and rotary intersections, the different level intersections are used for over pass and under pass.
2. An intersection that is provided for different levels of road is called __________
a) Intersection at grade
b) Grade separated intersections
c) Channelized intersection
d) Rotary intersection
Answer: b
Clarification: An intersection that is provided for different levels of road is called grade separated intersection, thus eliminating the crossing manoeuvre.
3. If the velocity of a vehicle is 60kmph and the other vehicle velocity is 20kmph, then the relative velocity is?
a) 80kmph
b) 40kmph
c) 20kmph
d) 60kmph
Answer: b
Clarification: The relative velocity is the difference of the velocities moving in same direction and sum of the velocities of vehicle moving in opposite direction.
4. If the angle of merging is low, then the relative speed will be __________
a) Low
b) High
c) Medium
d) Depends on width of pavement
Answer: a
Clarification: If the angle of merging is small, then the relative velocity will be low and impact will be low.
5. If an additional pavement is provided for lane change, then that intersection is called __________
a) Tee intersection
b) Rotary intersection
c) Flared intersection
d) Skewed intersection
Answer: c
Clarification: If an additional pavement is provided for lane change, then that intersection is called as flared intersection, it is provided in very crowded areas.
6. Which of the following is not a requirement for the intersection at grade?
a) Area of conflict should be large
b) Adequate visibility
c) Avoiding sudden change of path
d) Sufficient radius should be provided
Answer: a
Clarification: The intersection at grade requirements do not include large conflict area, it says the area of conflict should be as less as possible.
7. The most complex type of intersections for traffic operation is __________
a) Un-channelized
b) Channelized
c) Rotary
d) Grade separated
Answer: a
Clarification: The channelized intersections are the most complex type of intersections for traffic operation, but they are very easy to construct.
8. The procedure of adopting medians and traffic island in an un-channelized intersection is called __________
a) Dividing
b) Crossing
c) Channelizing
d) Designing
Answer: c
Clarification: The procedure of adopting medians and traffic island in an un-channelized intersection is called as channelizing of the intersection.
9. In India the design velocity at rotary is considered as __________
a) 30kmph
b) 40kmph
c) 50kmph
d) 60kmph
Answer: b
Clarification: In India, usually there is no limit to approach the rotary but for safety it is considered as 40kmph for design purposes.
10. If the coefficient of friction is 0.43, and the design velocity is 40kmph then the radius of curve is?
a) 20m
b) 25m
c) 28m
d) 30m
Answer: d
Clarification: The radius of curve is given by
R=V2/127f
R=40*40/ (127*0.43)
R=30m.
11. The minimum radius for rotary recommended by IRC is?
a) 1.3 times of entry radius
b) 1.33 times of entry radius
c) 1.5 times of entry radius
d) 1.7 times of entry radius
Answer: b
Clarification: IRC recommends an average radius of 1.33 times the entry radius for rotary design.
12. If the average width of the entry section is 3m and the exit is 6m then the average width is?
a) 4m
b) 4.5m
c) 5.0m
d) 5.5m
Answer: b
Clarification: The average width is average of entry and exit width
=3+6/2
=4.5m.
13. The PCU value near rotary is highest for __________
a) Cars
b) Bus
c) Cycle
d) Animal drawn vehicles
Answer: d
Clarification: The highest value for PCU near rotary is for animal drawn vehicle which is 4 to 6 PCU units.
14. In a traffic lane the traffic moving extreme left is 250 PCU and in extreme right it is 240 PCU, the sum of the weaving traffic crossing left and right is 500 PCU, find proportion of weaving traffic.
a) 0.5
b) 1.5
c) 2.5
d) 3.0
Answer: a
Clarification: b is the proportion of traffic entering into rotary, c is the proportion of traffic leaving the rotary, a is the proportion of traffic moving in the left lane and d is the proportion of traffic moving in the right line
P=b + c/ (a + b + c+ d)
P=500/ (250+500+240)
P=0.5.
15. The capacity of rotary in PCU per hour for a proportion of weaving traffic 0.5 and the width of weaving section is 12m, average width of entry is 0.4m and length of the weaving section is 7.2m.
a) 1088 PCU
b) 1100PCU
c) 1200 PCU
d) 1300PCU
Answer: a
Clarification: Qi = 280W [1+e/W][1-p/3] / (1+W/L)
Q=280*12*[1+0.4/12][1-0.5/3]/(1+12/7.2)
Q=1088PCU.