The link among density and accessibility is one of the critical factors in urban planning and transport planning [1
]. Many contemporary researchers have acknowledged the relationship between density, accessibility, and land use [2
]. In addition, density, land use, and accessibility factors have been identified as main characteristics of the urban form of the city [3
]. Therefore, urban planners and transport planers should have a profound understanding about the dynamic interactions between the characteristics of the urban form of the city. This is because the change of one component can influence the change of another. According to Hellervik, Nilsson, and Andersson, planners need to integrate land use and transport plans [3
]. Without a proper understanding about the static and dynamic relationships, planners cannot make a strategic intervention to achieve the envisaged urban form [4
]. Currently, planners mostly opt for the strategic planning approach which makes strategic interventions for planning issues. Nevertheless, most of the planning interventions fail to achieve the envisaged urban form of the plan. One of the main reasons is the lack of comprehension on the dynamic relationships between the major components of the urban form, particularly density, land use, and accessibility. When decision-makers are not clever enough to grasp the natural dynamic relationships of the urban form, the vision tends to be overlooked by these dynamics and turns towards an unforeseen direction. Nonetheless, the dynamics of the urban form will be continued reacting to the real ground situations. For instance, Windle [5
] mentioned that in Mumbai, India, the population density is 3230 per hectare whereas the maximum floor area ratio is 1:1.33. That numeral does not suit the existing and future population attractions to the city. Such population attractions have been driven by the accessibility and land use. Such problems could not have been occurred if the relationship among accessibility, land use, and population density had been modelled. That is the point where the derived urban form is going to be differed with the planners’ vision [4
]. Hence, a peculiar awareness of the urban form and its dynamic relationships is required for a desirable planning practices in the real ground applications. Most planners are aware of this relationship and its impact theoretically, but the models are not developed to capture that scenario numerically [4
]. Hence, most of the literature has explained the need for a quantitative framework to model the relationships among the aspects of the urban form [4
]. Identification of the relationship among the elements of the urban form is a valuable insight for decision-makers such as urban planners, transport planners, and engineers to make cities more sustainable. Accordingly, various empirical studies have been carried out to identify the relationship between elements of the urban form. Hillier and his team have developed the “space syntax” theory and technique to analyze these relationships between the aspects of the urban form. Recent empirical studies have been found that there is a robust association of the configuration of the urban form (accessibility) with factors such as employment [8
], density [10
], the distribution of land use [6
], and the distribution of activities in urban areas [13
]. However, in those studies, accessibility measurement was mainly considered the cognitive behavior of human movements, which is computed based on the topological-shortest-path, but the influence of the travel speed and roadway characteristics have not been considered [12
]. Jayasinghe et al. [12
] and Paul’s [15
] works have emphasized the importance of the impedance factor for account the travel speed and roadway characteristics. Furthermore, space syntax-based studies have mostly considered the two-dimensional connection among density and accessibility or land use and accessibility respectively [6
]. Recently, researchers have introduced new analysis tools such as “space matrix” and “mixed-use index,” to analyze the relationship between land use and density [18
]. Those studies have utilized the space syntax to compute the configuration (accessibility) of the street network; space matrix method to compute the degrees of building density; and mixed-use index to compute the degree of land use diversity [8
]. However, those studies have made limited attempts to model the three-dimensional relationship among density, land use, and accessibility (i.e., density ⟷ land use, density ⟷ accessibility, and accessibility ⟷ land use).
In such a context, this paper attempts to make a significant contribution to overcome the limitations noted in the emerging researches in the domains related to urban planning and transport engineering, through a novel modeling framework to capture and analyze the three-dimensional relationship among density, land use, and accessibility in urban areas, taking into account both topological and roadway characteristics.
The proposed framework is introduced in the next section. The materials and method are presented in the third section. Analysis and results are presented in the fourth section. This includes a relationship analysis among accessibility, land use, and densities in case study areas and model formulation. The conclusion and recommendations are presented in the last section.