The Influence of Road Dimensional Structures on User Attitudes: A Case of Urban Roads in Nairobi, Kenya

Abstract

The dimensional structure of urban roads, which encompasses both geometric and aesthetic dimensions, holds significance in determining road efficiency, safety, and user experience. However, despite the existence of frameworks acknowledging the importance of road aesthetics in road planning, there is no clear criterion for assessing road aesthetics. This study aimed to analyse user evaluative responses by assessing urban roads in Nairobi, with a focus on their dimensional structure and user attitudes operationalised as likability. It was hypothesised that there are underlying latent structures linked to aesthetics within Nairobi's urban roads that influence road likability. A mixed-methods strategy was adopted for collecting, analysing, and interpreting quantitative and qualitative data. A systematic review of the literature was conducted to reveal empirical evidence of dimensions used as indicators of road aesthetics, which were further evaluated against Nairobi urban road scenes. Correlations among variables were established through content analysis, text mining and statistical procedures, namely factor analyses and linear regressions. The exploratory factor analysis conducted on the likability scores identified coherence, naturalness, and imageability as the intrinsic aesthetic characteristics of Nairobi roads. A comparison of the geometric design elements with the results of the cognitive assessment of the aesthetic dimensions revealed a correlation between variables, and maintenance as the paramount factor. The results also showed that road user type, gender, age, and frequency of road use affected the perception of the visual dimensions. These results suggest that the cognitive load differences among road users have an impact on the self-explanatory nature of roads, highlighting the need for careful participant selection during stakeholder engagement in road planning. The findings offer valuable insights into the dynamics of road planning. Objective measures for quantifying and evaluating road aesthetics were identified. However, this study does not establish a definitive threshold for achieving optimal road aesthetics or directly measure its impact on user behaviours. Consequently, it suggests the need for the simulation of road environments to capture real-time user reactions, to develop a model that accurately depicts the direct impact of aesthetic dimensions on road user behaviour.