Introduction
Public urban spaces have traditionally been studied through Gehl’s framework of necessary, optional, and social activities. Emerging interactive technologies, however, are reshaping these patterns by mediating encounters and altering motivations, rhythms, and spatial use. Chaharbagh Abbasi in Isfahan, with its high walkability, mixed uses, and social significance, provides an ideal case to examine this shift. An agent-based model was developed to simulate how technology changes the distribution, co-occurrence, and intensity of these activities, revealing broader transformations in urban interaction.
The theoretical framework of this study builds upon classical and contemporary perspectives on urban space and social interaction. Traditionally, urban spaces have been shaped by cultural, social, and economic forces, and their vitality has been understood to depend on human presence and face-to-face interaction. Gehl’s typology of necessary, optional, and social activities emphasizes that improved environmental quality enhances opportunities for social interaction, reinforcing urban liveliness. Similarly, Lefebvre’s conception of space as both product and producer of social relations highlights the centrality of interaction in shaping urban identity.
In recent decades, rapid technological transformation has fundamentally reconfigured the meaning and function of urban space. With the emergence of interactive technologies, smart infrastructures, and spatial data networks, cities have evolved into hybrid environments where physical and digital layers coexist. Technology no longer acts merely as a supportive tool but as an interactive agent capable of shaping user behavior and mediating new forms of engagement. Consequently, interaction in contemporary urban space is no longer limited to human–human encounters; it now encompasses human–technology and technology–technology relations, giving rise to hybrid spatial experiences and redefining the components of interaction—actors, goals, temporalities, spatial settings, and modes of exchange.
These shifts challenge traditional urban design criteria, which relied primarily on human-scale, visibility, accessibility, and face-to-face engagement. As technological infrastructures become integral to urban experience, new criteria such as environmental interactivity, data integration, spatial adaptability, and responsive behavior emerge as determinants of design quality. Urban spaces must now support dynamic, multi-agent patterns of interaction shaped by both human and technological actors.
Grounded in this conceptual transition, the present research employs agent-based modeling to examine how evolving interaction goals—from human-human to human-technology and technology-technology—reshape behavioral patterns in urban environments. The study argues that understanding these transformations is essential for redefining urban design principles in the era of intelligent, interactive spaces.
Methodology
This applied study adopts a mixed-method (qualitative–quantitative) and descriptive–analytical approach to examine the reconfiguration of social interaction goals in contemporary urban spaces in the presence of interactive technologies. Field observations were conducted along the Chaharbagh-e-Abbasi axis in Isfahan at different times and seasons to identify patterns, types, and goals of social interactions. The collected data were coded into environmental, human, and technological variables and implemented in an agent-based model (ABM) comprising 1,500 human agents and mobile technology agents (based on an estimated 90% smartphone penetration rate). Sensitivity analysis was performed to assess the impact of spatial design factors and levels of technological presence on shifts in necessary, optional, and social interaction goals. Model validity was evaluated by comparing simulation outputs with empirical observations (RMSE = 0.0316; R² = 0.618), indicating acceptable predictive accuracy.
Discussion and result
The findings of the agent-based model demonstrate that urban design variables influence interaction goals in differentiated rather than uniform ways. Spatial–physical components primarily structure the conditions of interaction, while their intensity of influence varies across necessary, optional, and social activities. Functional attributes such as legibility, accessibility, and walkability show the strongest convergence with necessary activities, confirming their infrastructural role in stabilizing purposeful movement. However, these same variables indirectly support higher-level interactions by reducing spatial friction and enhancing perceptual clarity.
In contrast, spatial typology, flexibility, and land-use diversity exhibit greater impact on optional and social activities. Open, pedestrian-oriented environments—characterized by permeability and overlapping paths of movement and pause—demonstrate a stronger capacity to transform incidental encounters into intentional social engagement. This suggests that spatial organization does not merely enable activity occurrence but expands the potential for voluntary and socially oriented presence. Enclosure similarly reveals a dual effect: while not critical for necessary activities, it strengthens social interaction by reinforcing perceived security and sense of place.
Socio-cultural variables produce an even clearer divergence between necessary and social goals. Indicators such as density, perceived crowding, cultural diversity, inclusiveness, and sense of belonging consistently show stronger associations with social activities than with necessary ones. This pattern implies that while spatial form defines the structural framework of interaction, the depth and social intensity of engagement are largely shaped by the socio-cultural layer. Security, however, functions primarily as a prerequisite condition for purposeful action rather than a differentiating factor among interaction types.
Technological parameters emerge as reconfiguring agents within this multilayered system. In necessary activities, digital access and connectivity operate mainly as supportive infrastructure. In contrast, interactive tools, spatial intelligence, and adaptive technological features significantly increase the share of optional and social activities. Technology therefore shifts the motivation for presence from task-oriented necessity toward experiential and socially mediated engagement. Environmental qualities—including lighting, acoustic diversity, greenery, symbolic elements, and thermal comfort—act as perceptual mediators, regulating the experiential intensity of interaction rather than determining its occurrence.
The simulation results—2,616 interactions generated by 1,500 agents—indicate a structural redistribution of interaction goals: 24.7% necessary, 36% optional, and 39.3% social activities. The overlap of goals within individual agents, combined with 21.8% digitally connected (extra-spatial) interactions, reflects a transition from presence-based behavior toward hybrid, action-oriented engagement. In this configuration, urban space functions not solely as a site of functional necessity but as a dynamic arena of selective, socially oriented, and digitally mediated interaction shaped by the interplay of spatial structure, socio-cultural context, and technological capacity.
Conclusion
Thi study shows that high technological penetration fundamentally reshapes interaction gols in urban spaces. Necessary activities have shifted to digital layers, while optional ad social interactions dominate, often in hybrid forms. Technology drives exploratory ehaviors, extends interaction beyond physical presence, and creates a “digital–spatial identity.” Consequently, experiential qualities—such as legibility, activity diversity, greenery, comfort, and perceived safety—become critical. Chaharbagh exemplifies a multi-layered urban space where interaction is guided more by technological and experiential opportunities than by functional necessity.