it protects from tension and compression
It is any type of support beam or structure.
Superstructure
No it's not it's a noun.
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the substructure-gogodude32
Woodland Scenics N Scale roadbed typically measures about 2 inches wide. This size is designed to fit N scale track, which is 1:160 scale. The roadbed is made to provide a realistic base for model railroads while also helping with sound dampening and ensuring proper track alignment.
Gravel. Aka, Roadbed. Ballast is what they call it.
code 83
The term that defines the portion of the bridge above the roadbed is called the "superstructure." This part of the bridge supports the load and includes elements such as beams, girders, and trusses. It is crucial for transferring the weight of the bridge and its traffic to the substructure below.
roadwork(s) roadside roadway roadkill roadbed roadrunner roadster
Its not the speed over the roadbed that counts (all 3 are about the same) but the fact that unit trains do not need to be classified at each intermediary yard that makes them the "fastest".
Yes, it is like a bridge, but it is generally a natural formation. A causeway is a raised roadway or roadbed or natural bridge, usually over a body of water. A "bridge", in the majority of cases implies a man-made structure.