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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.
Heads of companies engaged in transportation of dangerous goods at the meeting with Head of the Main Directorate for Road Safety under the Interior Ministry Kanat Jumagaziyev on January 18 complained on the poor quality of the roadbed on the Bishkek - Osh highway, the patrol police reported.
Tenders are invited for Garbage truck with side loading SBM -301 2 on MAZ-4371 chassis with additional equipment (snow clearing is intended for cleaning of roadbed from fresh snow) or "equivalent"
The main damage to the road is that culverts are filled with ash and debris, as well as damage to the roadbed from heavy equipment operating across it during the fire," she wrote in an email.
During the construction process, the CA mortar of CRTS-I slab track is poured into the bag between track slab and concrete roadbed [6], which leads to the poor connections between CA mortar and track slab and between CA mortar and concrete roadbed.
The work will entail building a French drain to allow groundwater to migrate through the subsurface without damaging the roadbed.
roadbed and structures, devices, power, automation, remote control and communication, the official website of the SCR says.
Transitions to bridges should be smooth, and the roadbed should be compacted to provide stability (Federal Highway Administration, 2012b).
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 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.