Visual characteristics of roads: A literature review of people’s perception and Norwegian design practice

• Theoretical framework for assessing the visual quality of roads.
• Systematization of the terminology used in road aesthetics.
• Identification of 12 visual characteristics which influence the perception of roads.
• Identification of 42 relevant empirical studies regarding road design.
• A considerable deficit regarding the empirical backing for visual characteristics.

Several projects and measures have been developed to enhance the design of public roads. Nevertheless, the critics of their design remain numerous. To further the discussion on road aesthetics, this paper makes suggestions for a more consistent terminology and presents a theoretical framework for assessing the visual quality of roads. Based on a literature review, twelve visual characteristics are identified: coherence, imageability, simplicity, visibility, maintenance, naturalness, integration, contrast, variety, aesthetics of flow, legibility and orientation. These characteristics are presented and described and where possible their theoretical and empirical backing is given. Only a few visual characteristics in road design have been subjected to empirical perception studies, so their importance for road users and residents remains unclear.