Section 4: Aesthetics
It is the responsibility of the bridge designer to ensure that the structure meets the requirements for safety, durability, and cost. The engineer is equally obligated to consider the aesthetic impact of the bridge at its proposed location. Often, a utilitarian and plain structure efficiently satisfies the functional need. Increasingly, however, there is societal pressure to design a bridge that more harmoniously blends into and complements the particular site with attention given to the local architecture styles and culture.
The phrase that is most often used currently is context sensitive design, which simply points to a site-specific design integrating both function and aesthetics. While a particular design may take into account the local architecture close to the project, there are other design opportunities to propose a bridge that is unique to a site that otherwise has no nearby architecture from which to be inspired. As an example, consider a remote and lengthy water crossing where the future adjacent architecture may be influenced by that of the new bridge. Aesthetic decisions made at the time of the design must also take into account the anticipated adjoining land use during the life of the structure (generally taken as 75 to 100 years). A rural bridge today might be the focal point of a residential or resort area in 50 years.
The key to a successful aesthetic project is to build a unique and noteworthy structure — without breaking the bank. The team approach is recommended to determine the best style for the site, but as a bridge is an engineered structure, engineers must make the final decisions. The design team should take into account the input of bridge engineers experienced and accomplished in aesthetics, architects, landscape architects, artists, and other interested parties. Other valuable input has come from the public meetings process, where users, neighbors, and landowners are asked to participate and give their opinions. Again, the owner/engineer must take the responsibility for the final aesthetic decisions.
Bridges, by virtue of their size alone, are often works of public art. In consideration of their anticipated structural life of 75 years or more, they leave a lasting testimonial to the spirit and the priorities of those whose decisions shaped their look.