Horizontal alignment good practice: Identify the correct statement(s) about avoiding long tangents, minimum curve lengths for small deflection angles, and curve-omission thresholds during highway layout.

Introduction / Context:
Horizontal alignment aims to provide safe, comfortable vehicle guidance at design speed. Good practice limits excessively long tangents (which can induce speeding and monotony), ensures minimum curve lengths for appearance and comfort, and allows omission of very small curves when the deflection angle is extremely small and the transition can be treated as a tangent connection.

Given Data / Assumptions:

• Design speed consistent with highway class.
• Driver comfort and safety govern minimum curve lengths.
• Very small deflection angles may justify practical simplifications.

Concept / Approach:

Rules of thumb commonly guide preliminary layout before final checks for sight distance, superelevation, and widening. Avoiding very long tangents supports speed control and aesthetics; minimum curve lengths avoid a “broken-back” feel; and negligible deflections (under about 1°) may be treated as tangential to avoid awkward micro-curves that provide no real geometric benefit.

Step-by-Step Solution:

Verification / Alternative check:

These statements reflect design heuristics used alongside full checks: stopping sight distance, superelevation runoff, and transition lengths must still be satisfied.

Why Other Options Are Wrong:

• Any individual statement alone captures only part of good practice; collectively they summarize common guidance. Hence “All the above” is best.

Common Pitfalls:

• Relying on heuristics without verifying sight distance and comfort criteria.
• Omitting transitions on sharper curves.

Final Answer:

All the above.