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Showing posts from December, 2013

### One liners - Transportation Engineering for GATE, PSUs - Part 5

Hello there,
How have you been? Here is another round of one liners for your preparation for the GATE and PSUs examinations.

The diagram which shows the approximate path of vehicles and pedestrian involved in accidents is known as collision diagram.With increase in the speed of the traffic stream, the minimum spacing of vehicles increases.Traffic volume is equal to  traffic density * traffic speed.Practical capacity is also known as design capacity.With increase in speed of the traffic stream, the maximum capacity of the lane first increases and then decreases after reaching a maximum value at optimum speed.Equivalent factor of passenger car unit(PCU) for a passenger car as per IRC is 1.0.Scientific planning of transportation system and mass transit facilities in cities should be based on origin and destination studies.The diagram which shows all important physical conditions of an accident location like roadway limits, bridges, trees and all details of roadway conditions is known as …

### One liners - Transportation Engineering for GATE, PSUs - Part 4

Hello There,
I am here to give you another round of one liners from Surveying, for your preparation for GATE and PSUs.

For a constant value of co-efficient of lateral friction, the value of required super-elevation increases with, increase in speed and with decrease in radius of curve.To calculate minimum value of ruling radius of horizontal curves in plain, the design speed is given by 16 kmph.The attainment of super-elevation by rotation of pavement about the inner edge of the pavement avoids the drainage problem in the flat terrain.Psychological extra widening of pavement depends upon the speed of the vehicle.In case of hill roads the extra widening is generally provided on the inner side of the curve.The mechanical widening required for a n lanes road is given by   (nl^2)/2R where, l is the length of wheel base of vehicle in meters.As per the recommendation of IRC, spiral curve is used as the transition curve in the horizontal alignment of the highways.The lower among the values o…

### One Liners/MCQs- Transportation Engineering.- part 3

Hello,

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1. The camber preferred in concrete roads is

(a) Parabolic Camber (b) Straight Camber (c) Combination of parabolic and straight camber (d) Cubic
Ans: (b) Straight
2. The shoulders are preferred to be
(a) Paved (b) Rough (c) Smooth
Ans: (b)
3. To avoid overturning and lateral skidding, the centrifugal ratio and lateral friction must be  (a) Equal to b/2h (b) More than b/2h (c) Less than b/2h (d) 0   where b is the wheel base and h is the height of the center of gravity. Ans: (c)
4. When the longitudinal distance covered is more than the wheel circumferential distance, this phenomenon is called: (a) Sliding (b) Skidding (c) Overturning (d) Decelerating Ans: (b)
5. Nagpur road plan was based on