IRC Width of Formation for Major District Roads

The width of formation is a crucial parameter in road design, representing the total width of the road surface including the shoulders, measured from the top of the embankment or the bottom of the cutting. Indian Road Congress (IRC) provides guidelines for road dimensions based on the type of road, terrain, and traffic.

Understanding Width of Formation Standards

According to the recommendations provided by the Indian Road Congress (IRC) for hill roads and plain/rolling terrain:

• The width of formation is determined based on the road category and the type of terrain.
• For a Major District Road (MDR), which serves rural areas and connects smaller towns or important villages, specific dimensions are recommended.
• The question specifies a two-lane configuration on plain and rolling terrain.

IRC Guideline for Major District Roads

For a Major District Road (MDR) with two lanes on plain and rolling terrain, the Indian Road Congress (IRC) specifies the width of formation as follows:

• The standard width is $9 \text{ m}$. This typically includes the carriage way width and the shoulder widths on both sides.

Comparing this with the given options:

• 12 m
• $9 \text{ m}$
• $4.75 \text{ m}$
• $7.5 \text{ m}$

The correct width of formation as per IRC for a two-lane Major District Road on plain and rolling terrain is $9 \text{ m}$.