==Accessibility vs. Mobility==
Transit systems have been increasingly focused on accessibility when evaluating their systems and new projects. Although accessibility has always been a chief goal of transit, past measures have tended to focus on mobility, looking at the number of people who can access the transit system, system capacity, and line speeds. While improvements in service strengthen the transit system, these measures do not evaluate whether people have access to important destinations. Fast transit lines reaching many may nevertheless fail to connect people to job centers, grocery stores, or schools. Far reaching transit systems may force multiple transfers to reach a destination, such that the trip becomes
unreasonable long. Accessibility directly addresses these questions by measuring people's ability to reach desired destinations.
==Decay vs. Cut-offs==