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.
