Cross-sectional elements of a highway

The cross-section of a highway shows its elements in a section cut at right angles to the centre line. The main elements are:

|<-------------- Right of way ------------------>|
|<--------- Formation width -------->|
 _     shoulder   carriageway   shoulder     _
  \  ____________ ___/^\___ ____________  /
   \/ kerb/edge   camber crown            \/
 drain     ===========================   drain

1. Carriageway (pavement): the portion of the road meant for vehicles; it consists of lanes. Lane width is 3.0-3.75 m (3.5 m typical for NH), depending on class, speed and terrain (NRS 2070/IRC).
2. Shoulders: strips on both sides of the carriageway (1.5-2.5 m); used for emergency stopping, lateral support to the pavement and pedestrians.
3. Camber (cross fall): the transverse slope of the carriageway (2-3% for paved roads) to drain off water.
4. Kerbs: raised edges between the carriageway and the footpath/median (urban roads and bridges).
5. Median (central reserve): on divided highways, a strip separating opposite directions of traffic, with a width of 1.2 m (minimum) to 5 m (desirable).
6. Side drains: open drains beside the road, usually trapezoidal or triangular.
7. Side slopes: slopes of the embankment (e.g. 2H:1V, i.e. 2 horizontal to 1 vertical) or cutting.
8. Formation (roadway) width: carriageway + shoulders (+ median on divided roads); the top width of the embankment or the bottom width of the cutting, excluding the side drains.
9. Right of way (ROW): the total width of land acquired for the road, with allowance for widening, utilities and services (NRS 2070: 50 m for National Highways and 30 m for Feeder Roads).
10. Footpath, cycle track and service road: in urban stretches.
11. Roadside planting, guard rails, signs and boundary stones.
12. Building line and control line: the lines beyond which construction is restricted.