The designs that are used to build bridges are designs that can keep them stable , working and that won't be dangerous also designs that amaze people.
There are many designs such as
Concrete and steel .
The Romans used the arch to build large buildings and bridges.
depends on the bridge type really. most are steel and concrete.
brick,mud,wood
bridges are colapsing because they are old and the material that the people used is old or the people that built it did not build it right
yes they used bricks to build them
Metal and Steel ANSWER B: The majority of arch type bridges and viaducts were made from brick or stone. Concrete has also been used.
A bridgeis a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. There are many different designs that all serve unique purposes and apply to different situations. Designs of bridges vary depending on the function of the bridge, the nature of the terrain where the bridge is constructed, the material used to make it and the funds available to build it.
Americans used steel to build bridges and skscapers.
John Roebling
Iron is not used to build houses, but iron is used in other things because it is strong.
type 1