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 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for roadbed

Historical Examples of roadbed

  • On the other side of the track was a deep ravine, dropping abruptly from the roadbed.

    Spring Street

    James H. Richardson

  • The cut of the roadbed forms a base for the remainder of the snow.

    The White Desert

    Courtney Ryley Cooper

  • They landed beside the roadbed, and the cars went on without them.

  • He worked at the lever and touched the 202 valve, and then leaped from his post to the roadbed.

  • It was unsteady, indicating the uncertain character of the roadbed.

    Ralph on the Engine

    Allen Chapman

British Dictionary definitions for roadbed



the material used to make a road
a layer of ballast that supports the sleepers of a railway track
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012