As per I.R.C. recommendations, the approaches should have at least a minimum straight length of _______ on either side of a bridge
- A6 m
- B10 m
- C15 mCorrect
- D30 m
Solution
Concept
Minimum straight length of bridge approaches
Formula
NONE
Step-by-step solution
1. Bridge approaches ensure smooth, safe transition of vehicular movement on and off the bridge deck. 2. Curvature immediately adjacent to a bridge creates traffic hazards and uneven lateral distribution of load. 3. Indian Roads Congress (IRC) recommends a minimum straight alignment length of 15 m on both bridge approaches. Answer: C
Explanation
Bridge approaches require a straight alignment to allow vehicles to align smoothly before entering the bridge deck. The Indian Roads Congress guidelines recommend a minimum straight approach length of 15 meters on both ends of the bridge to ensure driver safety and sight distance. Thus, 15 m is the correct value.
Why the other options are wrong
A) 6 m is insufficient to provide proper sight distance and smooth alignment transition. B) 10 m is less than the standard 15 m minimum straight length recommended by IRC. D) 30 m exceeds the minimum required straight length of 15 m.
Shortcut
Bridge approaches require a minimum straight alignment of 30 m on either side.
Common mistake
Confusing the IRC recommended minimum straight approach length (15 m) with smaller bridge clearance lengths like 6 m or 10 m.
Correct answer: C) 15 m