Effects of Street-Facility Layout on Simulated Evacuation Under Simplified Fire Scenarios in a Commercial Pedestrian-Street Corridor in Chongqing: An Agent-Based Scenario Comparison

High-density commercial pedestrian streets are open urban spaces where commercial activities, public interactions, and everyday pedestrian movements are highly concentrated. However, they are also prone to crowd aggregation and local congestion during emergency evacuation. In mountainous cities, compact street spaces and terrain constraints may further amplify evacuation risks, while quantitative guidance for evacuation-oriented street-facility layout remains insufficient. To address this gap, this study investigates the effects of typical facility layouts on fire evacuation in high-density commercial pedestrian streets of mountainous cities. Using Chongqing, China, as a representative case, an AnyLogic agent-based evacuation model was developed for a 30 m by 90 m pedestrian-street segment with an initial density of 1.0 persons/m2. Archived surveys of 15 commercial pedestrian streets were used to identify recurring facility categories, geometric characteristics, and layout patterns rather than to reconstruct the surveyed streets as separate simulation geometries. Routine pedestrian-flow observations from two counting sections in the Three Gorges Square commercial center were used only for a qualitative ordinary-flow consistency assessment; they did not provide independent validation of emergency behavior under fire conditions. The simulations compared four clear edge-to-edge separation-barrier spacings, two archived advertising-board configurations, and a series of tree-pit-bench obstruction envelopes within an idealized 30 m × 90 m level corridor under simplified fire-related speed-reduction assumptions. Across the four tested barrier spacings of 800, 1100, 1400, and 1800 mm, the 95th-percentile evacuation time generally decreased as spacing increased. However, because only four spacing values were examined and 1800 mm was the only tested value above 1400 mm, the results do not establish an optimum spacing range or a response plateau. Differences were also observed between the archived advertising-board configurations and among the tested tree-pit-bench scenarios. The advertising-board comparison cannot be interpreted as a validated physical orientation effect because the original plan-view geometry could not be fully reconstructed. Similarly, the comparison between square and circular tree-pit-bench envelopes confounded boundary shape with occupied area and therefore does not demonstrate a pure shape effect. Most scenarios contained six simulation runs, and smoke, heat, visibility, toxic exposure, and mountainous terrain were not dynamically simulated. Accordingly, the findings are exploratory, model-specific scenario-comparison results and should not be interpreted as validated fire-safety thresholds or directly transferable engineering design requirements.