roadbeds
Rail line bases
Roadbeds are the foundations on which roads or railroad tracks are laid—the prepared surface of compacted earth, gravel, or other material that supports the pavement or rails above.
The term appears most often in railroad contexts: The old roadbed is still visible where the tracks used to run.
A well-constructed roadbed ensures stability and proper drainage.
Loose small rock fragments
- ballastShip stability material
- subgradeSoil layer supporting pavement
- compactionReducing volume through pressure
- gradingAssigning marks to work
fill · aggregate · drainage · excavation · embankment · leveling · foundation · crushed stone
Petroleum-based paving material
- pavementHard road covering
- shouldersUpper arm joints
- lanesParallel traffic divisions
- medianCentral sorted value
surface · erosion · potholes · resurfacing · underpass · culvert · retaining wall · overpass
Marks showing passage
- sleepersUnactivated spies or surprise hits
- tiesConnections or neckwear
- railsGuiding metal bars
- gaugeStandard of measurement
ballast · switches · crossties · alignment · grade crossing · right-of-way · locomotive · freight
gravel
Loose small rock fragments
- ballastShip stability material
- subgradeSoil layer supporting pavement
- compactionReducing volume through pressure
grading · fill · aggregate · drainage · excavation · embankment · leveling · foundation · crushed stone · soil
asphalt
Petroleum-based paving material
median · surface · erosion · potholes · resurfacing · underpass · culvert · retaining wall · overpass · maintenance
tracks
Marks showing passage
gauge · ballast · switches · crossties · alignment · grade crossing · right-of-way · locomotive · freight · maintenance
roadbedsrails
Guiding metal bars
tracks · road surface · superstructure · pavement · tarmac
roadbedsrolling stock
Wheeled railway equipment
vehicles · trains · traffic · locomotives · carriages