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a. The foundation upon which the ties, rails, and ballast of a railroad are laid.
b. A layer of ballast directly under the ties.
2. The foundation and surface of a road.


1. (Civil Engineering) the material used to make a road
2. (Civil Engineering) a layer of ballast that supports the sleepers of a railway track



a. the bed or foundation for the track of a railroad.
b. the layer of ballast immediately beneath the ties of a railroad track.
2. the material of which a road is composed.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.roadbed - a bed supporting a road
bed - a foundation of earth or rock supporting a road or railroad track; "the track bed had washed away"
road, route - an open way (generally public) for travel or transportation
safety island, safety isle, safety zone, traffic island - a curbed area in a roadway from which traffic is excluded; provides safe area for pedestrians


[ˈrəʊdbed] N (US) [of road] → firme m; [of railroad] → capa f de balasto
References in classic literature ?
The bridge seemed longer than it had ever seemed before, and he was glad when he felt the beat of the wheels on the solid roadbed again.
The work will entail building a French drain to allow groundwater to migrate through the subsurface without damaging the roadbed.
In Japan, in 2000, 95 per cent of waste concrete was reused as roadbed and backfilling material.
Kozak, is working with state officials to determine what, if any, of the old roadbed is actually state property.
The new design will widen the roadbed, straighten sharp turns, reduce steep gradients, and rebuild bridges and culverts to make it an all-weather road.
The highway utilized roadbed and unfinished tunnels from an abandoned railroad project of the 1880s to make the nation's first limited access, divided highway.
The new design will feature improved specifications that will widen the roadbed, straighten out sharp turns, and reduce steep gradients," the statement said, adding that the plans also included rebuilding bridges and culverts to make it an all-weather road.
From adding a roadbed to making a photographic backdrop, this focus on quality layout planning is a 'must' for any model railroad buff.
He said there was a very large break in the roadbed with the other side being much higher, so much higher that the car could not get over the break and instead lurched off the road and overturned.
This order was requested so we could replace the cracking concrete ties that have surfaced due to the high levels of uneven pressure exerted on the crossties where the bridge and roadbed meet.
The research team also determined the necessary pin sizes to provide controlled pressure relief and prevent roadbed damage for minor and moderate explosions.
The Phase 1 building under construction is located just 25 feet from the I-80 roadbed with an illuminated sign positioned 55 feet above the highway.