minimum length of shoulder recommended by IRC

Shoulders are provided along the road edge to serve as an emergency lane for vehicle compelled to be taken out of the pavement or roadway. Shoulders also act as service lanes for vehicles that have broken down.

Which gives cross section details of roads in embankment and cutting. The width of the shoulder should be adequate to accommodate stationary vehicle fairly away from the edge of the adjacent lane. It is desirable to have a minimum shoulder width of 4.6 m so that a truck stationed at the side of the shoulder would have a clearance of 1.85 m from the pavement edge.

The minimum shoulder width recommended by the IRC is 2.5 m.