Exploring dynamic accessibility gaps between urban village and commercial housing from the perspective of vertical inequity: a modified gravity model approach

Urban villages (UVs) are rural settlements encircled by urban built areas. Constrained by economic conditions, residents in UV predominantly rely on low-cost public transit for daily travel, even if it requires multiple transfers, i.e. multiple impedances. To address these challenges, this paper develops a modified gravity model (MG) to dynamically measure the employment accessibility(EA) of both UV and commercial housing (CH) across three time periods: morning peak hour (MPH), off-peak hour (OPH) and evening peak hour (EPH). The results demonstrate the MG's superior performance. The main findings are as follows:(1) The accessibility performance of both UV and CH shows significant variation across all periods. Moreover, the accessibility of CH is consistently higher than that of UV. (2) EA displays a spatial pattern of vertical inequity characterized by ‘high in the east and low in the west’. (3) In contrast, UV’ residents experience more severe vertical inequity in access to employment opportunities.