Hamburg has over 2,400. Hong Kong has more than 1,400. In Toronto, at least 1,000 dot the city. Bridges are a ubiquitous feature of urban landscapes, but until now, there have been no empirical studies asking what makes a bridge aesthetically pleasing to members of the public.
A new collaboration between cognitive scientists and civil engineers at the University of Toronto has spanned that gap.
“Bridges are such a part of our daily lives that we don’t even notice them most of the time,” says Claudia Damiano, a postdoctoral researcher with the Bernhard-Walther Lab. “But then there are some bridges that have become really iconic, like the Golden Gate Bridge or the Ponte Vecchio in Florence.”
“The question is: Why? Why are some bridges these iconic structures while others just fade into the background?”
To find out, researchers asked participants to rate 318 photographs of bridges on four different dimensions: aesthetic pleasure, perceived complexity, perceived interest, and perceived safety. They conducted additional tests to control for familiarity and assess rating consistency.
After collecting and analyzing their responses, the researchers found that people thought cable-stayed, suspension, and truss bridges to be more aesthetically pleasing, interesting, and complex than slab, frame, and girder bridges.
“Aesthetic complexity and interest have previously been found to be highly correlated, and our study corroborates that,” says Mei Yang, who graduated from the undergraduate research specialist program in psychology in 2024.
“People generally don’t like simple slab bridges, which would be your typical highway overpass,” says Damiano.
“Empirical aesthetics of bridges” was published in PLOS One by Yang and Damiano alongside psychology professor Dirk Bernhardt-Walther and civil engineering professor Paul Gauvreau.
Previously, only experts have weighed in on the question of what makes a bridge aesthetically pleasing—like architects and engineers. These discussions have largely been about striking a balance between aesthetic quality and cost.
However, it is often members of the public who finance the development, construction, and maintenance of bridges and live with the results for generations to come.
The researchers stress that as urbanization continues around the globe, collaborations between cognitive scientists who study the human experience and the engineers and designers who create our urban infrastructure are increasingly important.
The design of urban spaces has previously been connected to our visual comfort and navigation abilities, stress, mood, and overall life satisfaction. The insights drawn from these studies can inform future design choices to create more aesthetically pleasing bridges while balancing both practical and aesthetic needs.
For instance, Yang explains, this research can help engineers working on new bridges to more effectively conduct environmental impact studies and present design proposals during public consultations.
The study authors also performed an image feature analysis of each photograph to calculate a bridge’s length, orientation, curvature, and junction features. Interestingly, their findings run counter to the long-established “curvature effect” in empirical aesthetics which suggests that people prefer smooth curves over sharp angles. Here, high angularity and shorter contours in any particular bridge are associated with higher aesthetic pleasure, interest, and complexity ratings.
They propose that this may be because “structural art”– like bridges or towers – might rely on different factors for their aesthetic appeal compared to other forms of architecture or aesthetic objects like sculptures, paintings, and home decor.
This proposal requires additional study, the researchers note. Large structures, like cable-stayed and suspension bridges, are known to inspire awe and wonder. It is possible then that the aesthetic appeal of these types of bridges is connected to their real-world size, which participants may infer from photographs.
Damiano suggests that similar collaborations between cognitive scientists and engineers, architects, and urban planners can consider other features of our built environments to identify what makes them aesthetically pleasing – like green spaces in cities, murals, or smaller pedestrian bridges.
“We just touched the tip of the iceberg with this,” says Damiano.
More Information
To learn more about this study or to speak to its authors, please contact:
- Michael Pereira
Communications Officer, Department of Psychology, University of Toronto
psy.communications.officer@utoronto.ca