If a road surface has an inadequate superelevation on horizontal curve, then which one of the following is the correct statement?
- APressure on inner wheel is higher than the outer wheel
- BPressure on both inner and outer wheels is equal
- CPressure on outer wheel is higher than the inner wheelCorrect
- DNone of the above
Solution
Concept
Superelevation on Horizontal Curves
Formula
e + f = V² / (127 × R)
Step-by-step solution
1. Identify the superelevation formula: e + f = V² / (127 × R). 2. Note that if superelevation (e) is inadequate, the outward centrifugal force is not fully counteracted. 3. Observe that the unbalanced centrifugal force shifts the vehicle's weight outward, resulting in higher pressure on the outer wheels than on the inner wheels.
Explanation
When a vehicle turns on a curve, centrifugal force pushes it outward. If the road isn't banked enough (inadequate superelevation), this force shifts more of the vehicle's weight toward the outside, placing higher pressure on the outer wheels than on the inner wheels.
Shortcut
Remember: Inadequate banking pushes the vehicle outward due to centrifugal force, shifting weight to the outside. Think "Outward force = Outer wheel pressure."
Common mistake
Many students confuse inadequate superelevation with excessive superelevation and incorrectly select Option A, assuming that the vehicle tilts inward and places more pressure on the inner wheels.
Correct answer: C) Pressure on outer wheel is higher than the inner wheel