Thus, a holistic accessibility metric that encompasses the accessibility

Thus,
the concept of accessibility/mobility that started as a simple idea of a link
between transportation and land use (Warade 2007) has evolved in complexity and
is currently an intrinsic part of urban studies (Peralta-Quirós and Mehndiratta
2015). The development of land in a certain area is dependent on the
transportation access of the same area (Peralta-Quirós and Mehndiratta 2015).
An area with better accessibility is expected to have more development than
another area with lower accessibility. Thus, the demand for various
transportation modes to reach a certain location stems from the need to reach a
specific set of services offered by the said location (Peralta-Quirós and
Mehndiratta 2015). Planning and execution of transportation projects may
enhance the overall mobility of the city residents through efficiency gains,
time saving, lower congestion and increased access via public transit.
Transportation investments may increase the access to many, particularly the
marginalized section of the society, by providing links and access to various
city sectors (Peralta-Quirós and Mehndiratta 2015).  In particular public transit promotes
transportation equity, mitigates congestion and influences land use. Public transit
also provides environmental benefits and results in reduced energy consumption.
Most recently, accessibility has been defined (Peralta-Quirós 2015) as the
number of jobs, health care facilities, schools, and other essential services
that ?are available without a car in, say, 30–75 minutes—as a practical
criterion for judging the state of mobility and for designing ways to improve
it.  Using the accessibility criterion
will be critical to achieving SDG 11, the United Nations’ Sustainable
Development Goal to “make cities and human settlements inclusive, safe,
resilient and sustainable (http://www.un.org/sustainabledevelopment/cities/
)(Peralta-Quirós 2015). Hence, we want to develop a holistic accessibility
metric that encompasses the accessibility via not only the existing public
transport and privately owned automobiles but also via transportation modes
provided by transport network companies. 
This accessibility measure should be readily adaptable and applicable to
automated mobility districts as well.