The concept of accessibility has acquired numerous meanings along multiple dimensions during the century of its evolution. This essay argues for the salience of two dimensions: application-based and definition-based. In its application, accessibility has incorporated positive and normative dimensions which have varied in prominence over time. In its definition, accessibility has varied between a mode of evaluation incorporating measured mobility and proximity, on the one hand, and a predefined market basket of urbanist improvements to transportation and land use systems, on the other. Advocates of the accessibility shift should emphasize both the measured approach to accessibility and accessibility’s normative side.

可访问性的概念在其演变的一个世纪中已在多个维度上获得了多种含义。本文主张两个方面的突出性：基于应用程序和基于定义。在其应用中，可访问性已纳入了积极的和规范的方面，这些方面的重要性随时间而变化。就其定义而言，可访问性在一方面包括结合了测得的流动性和邻近性的评估模式与另一方面对交通和土地使用系统进行城市化改进的预定义市场篮之间有所变化。提倡无障碍获取的倡导者应同时强调衡量可访问性的方法和可访问性的规范方面。