In the design of a horizontal curve, super-elevation is provided to
- ACounteract the effect of centrifugal force.
- BPrevent the vehicle from skidding or overturning.
- CAllow higher speeds on the curve.
- DAll of the aboveCorrect
Solution
Concept
Superelevation on Horizontal Curves
Formula
e + f = V² / (127 × R)
Step-by-step solution
1. Identify the purpose of providing super-elevation (e) in horizontal curve design using the relationship e + f = V² / (127 \* R). 2. Recognize that super-elevation counteracts centrifugal force, prevents skidding or overturning, and allows vehicles to travel safely at higher speeds. 3. Compare all options and select Option (d) "All of the above" as the correct choice.
Explanation
Super-elevation is the raising of the outer edge of a road above the inner edge along a curve. This inclination helps counteract the outward centrifugal force acting on a vehicle, which prevents it from skidding or overturning and allows drivers to travel safely at higher speeds. Therefore, all the statements are correct.
Shortcut
To remember all benefits of Super-elevation on horizontal curves, use the mnemonic "CSA" (Counteract, Safety, Speed): - Counteract: Counteracts the outward centrifugal force - Safety: Prevents the vehicle from skidding or overturning - Speed: Allows higher safe travel speeds on curves
Common mistake
A common mistake is selecting Option A immediately after recognizing that superelevation counteracts centrifugal force, without reading Options B and C. Since preventing skidding or overturning and allowing higher safe speeds are direct benefits of counteracting centrifugal force, all options are correct, making Option D the correct choice.
Correct answer: D) All of the above