Accessibility measures have been extensively used to explore the outcomes of the spatial distribution of transport, jobs, and population groups in cities. Despite its wide use, identifying the population groups that most benefit from accessibility is not straightforward and different metrics might result in different conclusions. The present work aims to analyze the potential bias of using gravity-based measures based on revealed mobilities to identify job accessibility inequalities. By looking at two large and very different regions, the municipality of São Paulo (SP) and the Greater London Area (GLA), we argue that distance decay functions built from current trip behaviors should be carefully used in evaluations of accessibility inequalities because it may underestimate disparities between socio-occupational groups and also result in a misleading interpretation of impedance factors. Two distinct approaches were implemented to support those claims. We first estimate group-specific distance decay functions, considering only travel time. Secondly, we consider both travel time and travel cost relative to income to estimate zone-specific and city-specific distance decay functions for each one of the study areas. The population of both cases studies was stratified according to the NS-SEC standard to select the highest and the lowest socio-occupational groups and to explore job accessibility inequalities. It was found that higher-level and lower-level socio-occupational groups of SP and GLA present striking differences in terms of travel times and relative travel costs, with SP being more unequal. By applying the distance decay function of the lowest level socio-occupational group to the calculations of the job accessibility of the highest level group, and by adding travel cost to the analysis, we highlight inconsistencies between gravity-based accessibility calculations and theory, as trips taken by different groups can be mistakenly associated with willingness to travel. From a policy perspective, our findings emphasize that accessibility inequalities in large urban centers, especially in the Global South, can be underestimated if revealed mobilities are considered to represent the willingness to travel and by not taking into account the relative cost of travel.

可达性措施已被广泛用于探索城市交通、就业和人口群体空间分布的结果。尽管其用途广泛，但确定从可访问性中受益最多的人群并不简单，不同的指标可能会导致不同的结论。目前的工作旨在分析使用基于揭示的流动性的基于重力的措施来识别工作可及性不平等的潜在偏见。通过观察两个大而不同的地区，圣保罗市 (SP) 和大伦敦地区 (GLA)，我们认为，根据当前出行行为构建的距离衰减函数应谨慎用于评估可达性不平等，因为它可能低估社会职业群体之间的差异，并导致对阻抗因素的误导性解释。实施了两种不同的方法来支持这些主张。我们首先估计特定组的距离衰减函数，仅考虑旅行时间。其次，我们考虑相对于收入的旅行时间和旅行成本，以估计每个研究区域的特定区域和特定城市的距离衰减函数。根据 NS-SEC 标准对两个案例研究的人群进行分层，以选择最高和最低的社会职业群体，并探索工作可及性的不平等。研究发现，SP 和 GLA 的较高级别和较低级别的社会职业群体在旅行时间和相对旅行成本方面存在显着差异，其中 SP 更加不平等。通过将最低级别社会职业群体的距离衰减函数应用到最高级别群体的工作可达性计算中，并通过在分析中增加旅行成本，我们强调了基于重力的可达性计算与理论之间的不一致，如旅行不同群体所采取的行动可能会被错误地与旅行意愿联系起来。从政策的角度来看，我们的研究结果强调了大城市中心的可达性不平等，特别是在全球南方，