National Highways – minimum pavement (carriageway) width The minimum width of the paved carriageway (pavement) provided for a standard two-lane National Highway is typically:

Introduction / Context:Two-lane National Highways are designed to accommodate opposing traffic safely at design speeds. The carriageway width must be sufficient for typical heavy vehicles with lateral clearance.

Given Data / Assumptions:

• Standard two-lane section without median.
• Conventional lane width ≈ 3.35 m per lane in some traditional specifications.
• Paved shoulders excluded from the stated carriageway width.

Concept / Approach:Using a lane width of approximately 3.35 m per lane for two lanes gives a typical minimum carriageway width of 6.7 m. (Note: Some modern standards adopt 3.5 m lanes, giving 7.0 m, but the commonly cited minimum legacy value associated with 3.35 m lanes is 6.7 m.)

Step-by-Step Solution:

Verification / Alternative check:Textbook cross-section tables list 6.7 m as a standard two-lane carriageway width where 3.35 m lanes are adopted; with 3.5 m lanes, the value becomes 7.0 m (beyond the given options).

Why Other Options Are Wrong:4.7 m and 5.7 m are too narrow for safe two-way heavy-vehicle operation; 7.7–8.0 m exceed the typical minimum and would represent wider lanes or added paved shoulders.

Common Pitfalls:Mixing up carriageway width with roadway or formation width; assuming paved shoulders are part of the stated carriageway.

Final Answer:6.7 m