cross section of a road

Road: thoroughfare connecting two geographical points, usually urban centers.

solid line

Line demarcating the edge of the roadway or, when in the center of the roadway, indicating that passing is prohibited.

broken line

Line demarcating the two lanes of the roadway and showing that passing is permitted.

subgrade

Layer supporting the base course and the subbase and providing drainage.

slope

Steeply sloped ground between the ditch and the bank and between the ditch and the shoulder.

ditch

Ditch parallel to the roadway; surface water drains into it.

subbase

Base of a roadway, made up of coarse compacted gravel, making the roadway solid and stable.

bank

Natural land along the edge of the road.

base course

Top foundation layer, made up of fine compacted material; the driving surface lies on it.

shoulder

Area between the roadway and the ditch, providing the roadway lateral support; it is also a place for emergency stops.

bed

Composed of the embankment and the earth foundation; the base rests on it.

earth foundation

Part of the ground that was not excavated during the road’s construction.

embankment

Layers of material used to build up or level the route the road is to take.

base

Series of layers above the embankment reducing stress exerted by the traffic and preventing the bed from deforming.

surface course

Roadway’s driving surface; it is smooth, impermeable and provides a good grip for vehicles.

roadway

Surface upon which vehicles drive.