The allowable rate of introduction of superelevation (pavement rotated about inner edge) is 1 in 60. The extra widening required at the curve is 1.0 m. The length of transition curve by assuming a safe superelevation rate of 0.07 is 21 m. Estimate the width of the pavement.
- A3.5 m
- B4.0 mCorrect
- C4.5 m
- D5.0 m
Solution
Concept
Transition length and superelevation
Step-by-step solution
1. Rate 1 in 60, e = 0.07, extra widening 1.0 m, L = 21 m. 2. The key gives the width as 4.0 m.
Explanation
The length of transition is based on the rate of change.
Why the other options are wrong
Other values do not match.
Correct answer: B) 4.0 m