WIDTH OF CARRIAGE WAY
Width of the carriage way or the width of the pavement depends on the width of the traffic lane and number of lanes.
Width of a traffic-lane depends on the width of the vehicle and the clearance.
The maximum permissible width of a vehicle is 2.44 and the desirable side clearance for single lane traffic is 0.68m. the required minimum lane width is 3.75m for a single lane road and for double lane, however the side clearance required is about 0.53m, on either side on 1.06m in the center. Therefore a two lane road requires minimum of 3.5m for each lane. The desirable carriage way width recommended by IRC is given in table :
IRC specification for carriage way width
Single lane | 3.75 |
Two lane, no kerbs | 7.0 |
Two lane, raised kerbs | 7.5 |
Intermediate carriage | 5.5 |
Multi-lane | 3.5 |
Intermediate carriage way is more than one lane but less than two lane. This is provided to give maneuvering.
Where the carriageway width changes, e.g., from single lane to two lanes or two lanes to four lanes, the transition should be affected through a taper in 1 in 15 to 1 in 20.
