When it comes to architecture one of the most important aspects is bridge design. Bridges must be two things, functional and aesthetically pleasing. A bridge needs to sufficiently span the necessary gap but also fit well with other structures in the area.
In the past, especially the steel revolution, when bridges were focused on functionality. While they are huge and something to look at the bridges of that are were built for functionality. They had a huge job to preform supporting trains and newly invented automobiles. You can get more information about it on this website.
Farther in the past, however, in ancient times the invention of the arch made for beautiful structures bridges among them. A simple arch was sufficient, back then, to handle any of the weight they had to handle.
Today bridges have the luxury of being both super strong and beautiful. Stronger and more durable materials help improve the bridges and advanced math allows us to design structures that were not possible in the past. These advancements allow for structures that are just as beautiful as strong.