The GATE Grind

GATE 2022 CE (CE1) – Question 28

Transportation Infrastructure · Geometric design of roadways: cross-section, sight distance, alignments · 1 mark · Multiple select

A horizontal curve is to be designed in a region with limited space. Which of the following measure(s) can be used to decrease the radius of curvature?

  1. Decrease the design speed.
  2. Increase the superelevation.
  3. Increase the design speed.
  4. Restrict vehicles with higher weight from using the facility.

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Show answer and explanation

Correct answer: (A) Decrease the design speed.; (B) Increase the superelevation.

Explanation

The horizontal-curve relation is $R=V^2/[127(e+f)]$ for V in km/h. Lower design speed decreases the numerator; larger superelevation increases the denominator.

Both changes permit a smaller radius. Increasing speed does the opposite, and the simple equilibrium relation is independent of vehicle weight. **Answer: A and B**.