Definition of "roadbed" [road•bed]

• The foundation upon which the ties, rails, and ballast of a railroad are laid. (noun)
• A layer of ballast directly under the ties. (noun)
• The foundation and surface of a road. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Unfortunately the roadbed is very poor, so the new repairs deteriorate rapidly."
• "But note that there are some long stretches where the roadbed is not that great, with the top inch or so of pavement peeling badly, especially in the right-hand lane."
• "We simply say that the west provided the money, and the road has been built up to mile 332 with the very finest road bed in Canada, with 80-pound steel rail, and from Kettle Rapids to Nelson, 91 miles, the roadbed is just waiting for the ties and rails."