Highway Engineering

Step 1: Formula for Intermediate Sight Distance (ISD).
The intermediate sight distance (ISD) is taken as twice the stopping sight distance (SSD).

Step 2: Substitution.
Given that SSD = 80 m, we have:

Step 3: Correction with respect to Passing Sight Distance.
As per IRC recommendations, ISD is the average of SSD and PSD when both are provided:

Step 4: Conclusion.
Hence, the intermediate sight distance is 190 m, so the correct answer is (A).

Step 1: Formula for Length of Summit Curve (L).
For summit curves where : where, - = algebraic difference of grades = , - (driver's eye height), - (obstruction height), -

Step 2: Substitution.

Step 3: Conclusion.
Therefore, the required length of the summit curve is 322 m. Hence, the correct answer is (C) 322 m.

Step 1: Formula for equilibrium super elevation.
The super elevation is given by: where, - - -

Step 2: Substitution.

Step 3: Conclusion.
The equilibrium super elevation is approximately 4.6%. Hence, the correct answer is (C) 4.6%.

Step 1: Formula for traffic capacity.
The theoretical maximum capacity is given by: where, - - (center-to-center spacing).

Step 2: Substitution.

Step 3: Conclusion.
The maximum theoretical capacity of the highway lane is 4391.84 vehicles per hour. Hence, the correct answer is (A) 4391.84.

Step 1: Transition curve design criteria.
Transition curves are introduced in highways to provide gradual change in curvature and superelevation. The key parameters are: - Rate of change of radial acceleration. - Rate of change of superelevation. - Rate of change of curvature.

Step 2: Eliminate unnecessary parameter.
Rate of change of grade (longitudinal slope) is not a governing factor in transition curve design.

Step 3: Conclusion.
Hence, the required parameters are (B), (C), and (D). Therefore, the correct answer is (D).

Step 1: Understanding traffic capacity.
Traffic capacity is the maximum number of vehicles that can pass a given point on a lane or roadway during a specified time period under prevailing conditions.

Step 2: Analysis of options.
- (A) Correct: This matches the standard definition of traffic capacity (vehicles per hour).
- (B) Incorrect: This defines traffic density, not capacity.
- (C) Incorrect: This relates to physical width, not capacity.
- (D) Incorrect: This defines speed, not capacity.

Step 3: Conclusion.
Hence, traffic capacity is correctly defined as option (A).