Determinants of pavement (carriageway) width The selected pavement width for a road section primarily depends upon which factors?

Introduction / Context:
Pavement width is a basic geometric design input. Oversizing wastes money; undersizing compromises safety and capacity. Designers weigh multiple context-specific factors before finalizing the carriageway width.

Given Data / Assumptions:

• Rural highway context.
• Design speed consistent with terrain.
• Traffic mix typical of national/state highways.

Concept / Approach:
The lane width and number of lanes depend on traffic volume and composition. Terrain controls alignment, sight distance, and clearances, often constraining widths in hills. Heavier traffic and more lanes call for wider carriageways and shoulders for safety and capacity.

Step-by-Step Solution:

Verification / Alternative check:
Cross-section standards tabulate different widths for single-lane, two-lane, and multi-lane roads, and provide relaxations/exceptions for mountainous regions, confirming multi-factor dependence.

Why Other Options Are Wrong:
Each single factor (A–C) influences width; only the combined statement covers all primary determinants.

Common Pitfalls:
Applying plain-terrain standards to hills; neglecting future widening provisions or median needs in staged construction.

Final Answer:
All the above