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.
Theoretical Framework
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 used a mixed-method and descriptive-analytical approach to examine how interactive technologies reshape social interaction goals in urban spaces. A systematic review of 120 articles and field observations along Chaharbagh-e-Abbasi in Isfahan identified key environmental, human, and technological variables, which were integrated into an agent-based model (ABM). Sensitivity analysis assessed the influence of design and technological factors on interaction goals, and model reliability was confirmed (RMSE = 0.0316; R² = 0.618).
Results and Discussion
The systematic review of ISI publications (2019–2024) and comparison with recent empirical studies indicate that physical variables remain the primary drivers shaping the three classic categories of interaction goals—necessary, optional, and social activities—despite the growing influence of digital technologies. Urban space type, spatial legibility, accessibility, flexibility, functional diversity, enclosure, and scale each exert distinct effects on interaction goals, with open public spaces showing the highest capacity for social interactions. Social–cultural variables, including population density, perceived crowding, cultural diversity, social inclusiveness, and sense of belonging, were found to play an even deeper role in shifting interactions from necessary toward optional and social forms.
Technological parameters—such as digital connectivity, public Wi-Fi, sensor density, interactive devices, adaptive spatial programming, and affordability of digital services—demonstrated a transformative influence, expanding hybrid (physical–digital) interactions and significantly increasing optional and social activities. Environmental variables such as lighting, acoustic diversity, symbolic elements, greenery ratio, and thermal comfort functioned as perceptual mediators that strengthened or weakened the likelihood of different interaction goals.
The agent-based model developed for Chaharbagh-e Abbasi simulated 1,500 human agents and technology-augmented agents based on the identified parameters. Using a logistic choice model with normal noise allowed agents to simultaneously pursue one or more goals, reflecting contemporary hybrid behavior patterns. The model generated 2,616 interactions, showing that agents, on average, performed more than one purposeful action—indicating a shift from “presence-based behavior” to “action-based behavior.” The distribution of interactions revealed a structural change in public-space use: 24.7% necessary, 36% optional, and 39.3% social activities. This confirms a declining dependence on physical space for necessary tasks and a growing dominance of selective, experiential, and socially oriented presence.
Model outcomes illustrated that social and optional activities often co-occurred, producing fluid, short-lived, and rapidly forming clusters—consistent with Whyte’s observations of group dynamics in pedestrian spaces and intensified by digital mediation. Furthermore, 21.8% of all interactions were connected to individuals or services outside the physical space, reflecting the emergence of “connected presence” and the dissolution of spatial–temporal boundaries. Overall, the findings show that while physical and socio-cultural variables structure interaction patterns, technological parameters fundamentally redefine interaction goals, driving a transition toward hybrid, optional, and socially oriented behaviors in contemporary urban public spaces.
Conclusion
This study shows that high technological penetration fundamentally reshapes interaction goals in urban spaces. Necessary activities have shifted to digital layers, while optional and social interactions dominate, often in hybrid forms. Technology drives exploratory behaviors, 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.