Please clarify.
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.
Some websites that have pictures of bridge designs are: Highest Bridges, Garretts Bridges, Historic Bridges, Bridge Element, Design Bridge and Google Images.
Civil Engineers.
civil engineers, structural engineers, and architects are the main bridge builders.
an engineer who designs and maintains roads, bridges, dams, and similar structures.
Civil Engineers and Architects design bridges and buildings.
An engineer is a person who designs and builds bridges, structures, engines, machines, or public works. A specialist is someone who concentrates on one particular thing, such as bridges.
Enginers build bridges but it costs a lot of money $$$$$$$$$$$$$$$$$$$$$$$
The arch bridge design makes it stronger because it has support underneath
One can look for the best images of bridge image designs on sites such as Wikipedia and Blueprints. There you will find just about anything that you will need to know about bridges.
Yes there were truss bridges in Europe before the United States. Truss bridges formed in the US because of Europeans, but new American designs were made and that is why the truss bridge is more abundant in the US than Europe today.
One may use the information on Wikipedia to learn more about bridge designs. They have pictures and pages for many types of bridges found all over the world.