Bridges & Aesthetics

Society recognizes the positive influence of transportation infrastructure, despite the environmental and visual impacts. Unfortunately, poor aesthetics in our projects have also led to society having a distorted perception of these civil engineering structures.

A world unconcerned about aesthetics or culture would be as flat, sad and hopeless as the austere existence of Winston Smith in George Orwell’s novel 1984. Could you imagine each person wearing the same clothes just for the sake of economic efficiency?

The human cognitive response to aesthetics is complex. Different cultural movements and approaches lead to different aesthetic preferences, but whatever the preference, they result in positive intellectual and visual experiences. A beautiful bridge results in joy, nurturing pride and positive feelings in its community. Therefore, it is a legacy of excellence for generations to come.

Aesthetically attractive bridges are not necessarily expensive structures. We associate aesthetic designs with added costs only if we understand aesthetics as an ornament to what is built, and not as something that is intrinsic to the bridge itself. Decoration increases the construction cost but aesthetics itself does not. Most of the beautiful bridges in the past two centuries have been design-build projects and are both efficient and economical.

The field of industrial design has been able to generate aesthetically pleasant and inexpensive products adapted to clients. A civil engineer’s real challenge and civic duty is to conceive attractive and elegant bridges with a negligible impact on cost. At the same time, in the author’s opinion, a rational increase of cost is always acceptable. If it is grounded in ethics and sustainability, the design increases the bridge value and society’s assets along with it.

If cost is confused with value, the most economical will be seen as the best solution. But the consequences of this approach in bridge design have led to both extremes of deficiency and excess: on one hand the standardization of short and medium span bridges that underestimate appearance and context; on the other hand the construction of iconic bridges to serve economic interests that often prevail over both global public interest and sustainable development.

Signature extravagance

Post-modernity has brought about impersonal spaces, globalization (loss of diversity of cultural expressions), and the Disneyfication of society and its bridges. Signature bridges are not often built, but when they are they have a great impact in the media. The greater the need of a society to reaffirm itself, the greater is its necessity of material symbols. Therefore, works are built that are extravagant, inefficient structural concepts, out-of-scale bridges that are extremely expensive, a maintenance burden and unsustainable. Every city that’s “worth its salt” wants to have a cable-stayed bridge. If the bridge is “designed” by a media celebrity architect it is considered even better.

The general perception is that good bridges are designed by architects, and engineers are just required to make possible what these more creative professionals design. This attitude may be the end of structural engineering as a creative profession. The participation of other professionals (artists, architects or urban designers) could be beneficial but it should not be a must. The engineer should always lead the concept and detailed design.

How can we design appealing bridges?

Signature bridges should be designed without excesses.

Aesthetics does not occur by chance or by trivial imitation. The engineer should devote care and attention to the type and form, the dimensions, proportions and scale, the structure’s order, rhythm, texture, colour, wise use of materials, and refinement of details. Expression of culture and technology, and other visual design elements are also important considerations. There are a myriad of design alternatives for the various parts and the bridge as a whole.

Intuition, imagination and creativity are a must to make expressive structures that are in harmony with the site and its history. Aesthetics along with sensitivity and understanding of the context are fundamental triggers of a high quality bridge. The design of a good bridge, no matter its size, requires time and effort. We should take up the challenge.cce

Juan Sobrino, Ph.D., P.Eng., P.E. is chief executive officer at Pedelta Canada, based in Toronto. He founded the company in Barcelona, Spain 20 years ago. He is an adjunct professor at Carnegie-Mellon University and an active member of several international bridge technical associations.