Nagpur recommendations (rural two-way): The recommended width of paved carriageway for two-directional traffic, in addition to gravelled berms 1 m wide on either side, is approximately

Introduction / Context:
Historic Indian highway standards (Nagpur Conference) provided baseline carriageway and shoulder widths for rural roads. For two-way, two-lane traffic on lower to moderate volumes, a standard paved width with gravelled berms was recommended to balance safety and economy.

Given Data / Assumptions:

• Two-directional traffic on a rural road.
• Gravelled berms of 1 m provided on both sides (total 2 m of berm).
• Carriageway width sought (paved portion only).

Concept / Approach:

Under the Nagpur plan era recommendations, a typical two-lane rural carriageway width near 5.5 m was common. In metric rounded values used in many texts and question banks, 5.5–5.7 m appears, paired with 1 m gravelled berms each side to give adequate total formation width and lateral safety margin.

Step-by-Step Reasoning:

Verification / Alternative check:

Later standards (IRC) refine widths based on lane width (for example 3.5 m per lane), but the referenced historical recommendation in this question aligns with ≈5.5–5.7 m paved width for two-way traffic on lower-volume roads.

Why Other Options Are Wrong:

• 4.7 m: too narrow for comfortable two-lane operations.
• 6.7–8.7 m: represent wider facilities or multi-lane/bus-bay provisions, not the classic baseline.

Common Pitfalls:

• Confusing total formation or ROW with paved width.
• Mixing modern lane standards with older plan recommendations without context.

Final Answer:

5.7 m.