Which of the following is the correct value of maximum superelevation to be provided for the roads in hilly terrain with no snow?
- A2%
- B4%
- C7%
- D10%Correct
Solution
Concept
Maximum Superelevation Limits
Formula
e + f = V² / (127R)
Step-by-step solution
1. Identify the terrain condition: Hilly terrain without snow bound areas. 2. Refer to IRC guidelines for maximum superelevation limits: 10% for hilly terrain, 7% for plain/rolling terrain, and 4% for urban roads. 3. Select the correct option: 10% (Option D).
Explanation
As per Indian Roads Congress (IRC) guidelines, the maximum superelevation for roads in hilly terrain without snow is set at 10%. This higher banking angle allows vehicles to navigate steep, sharp curves safely without slipping or overturning.
Shortcut
Remember the "4-7-10" rule for maximum superelevation: - Urban roads = 4% - Plain/Rolling terrain (and Snow-bound hills) = 7% - Hilly terrain without snow = 10%Shortcut: "Higher hills with no snow take the highest superelevation (10%)."
Common mistake
Students commonly confuse the IRC maximum superelevation limit for hilly terrain bound by snow (7%) with hilly terrain not bound by snow (10%), leading them to select Option C (7%) instead of Option D (10%). Additionally, some confuse it with the limit for plain and rolling terrain (7%) or urban areas (4%).
Correct answer: D) 10%