roadbed

[ rohd-bed ]
/ ˈroʊdˌbɛd /

noun

Railroads.
  1. the bed or foundation structure for the track of a railroad.
  2. the layer of ballast immediately beneath the ties of a railroad track.
the material of which a road is composed.

Origin of roadbed

1830–40. Americanism; road + bed

Example sentences from the Web for roadbed

British Dictionary definitions for roadbed

roadbed
/ (ˈrəʊdˌbɛd) /

noun

the material used to make a road
a layer of ballast that supports the sleepers of a railway track