They can be applied descriptively to identify lack of accessibility to essential services in certain areas (i.e. to take stock of accessibility gaps). They can also be used to assess how various policy or infrastructure alternatives might change accessibility levels across territories and for different users, demonstrating how given options would contribute to or undermine the attainment of wider sustainability goals. Additionally, accessibility indicators can be used in ex post analysis, comparing a previous situation to the current one after implementation of a specific action.