Reworking assumptions of vertical accessibility modelling within critical GIS through autoethnography

GIS-based pedestrian accessibility models commonly assume bodily uniformity, infrastructural stability and route redundancy. In vertically complex cities, these premises overlook how mobility depends on the operation and orientation of lifts and escalators. This article reconceptualises vertical accessibility as a socio-technical condition shaped by infrastructural reliability and embodied capacity rather than as a purely geometric attribute of three-dimensional networks. Grounded in fourth-wave critical GIS and disability scholarship, we integrate Hong Kong’s 3D pedestrian network modelling with collaborative autoethnography, using lived experiences of disability, caregiving and ageing to inform structural revisions to network representation, including escalator directionality and facility-specific vulnerability simulation. Geo-computational analysis reveals concentrated facility dependence: a single lift appears in up to 20 shortest paths for mobility-limited groups, and simulated outages generate vulnerability scores nearly seven times higher for wheelchair users than for individuals without limited mobility. Excluding operational attributes systematically overstates accessibility, while uphill-oriented escalators can produce 30–50-m downward detours that reallocate bodily effort and risk in ways conventional impedance-based models cannot capture. By situating experiential insight upstream of computational design, the study reworks vulnerability as infrastructural dependence and positions accessibility modelling as a reflexive practice that shapes how independence, resilience, and exclusion are organised in vertical cities.