road metal

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Crushed or broken stone, cinders, or similar material used in the construction and repair of roads and roadbeds.

from The Century Dictionary.

• noun Broken stone, etc., used for making roads: same as metal, 6.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun broken rock used for repairing or making roads