it protects from tension and compression
It is any type of support beam or structure.
Superstructure
No it's not it's a noun.
span
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
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.
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern --ADB--. That is, seven letter words with 3rd letter A and 4th letter D and 5th letter B. In alphabetical order, they are: deadboy roadbed