  The Cumulative Drag Index defined recently by Prasanna has been generalised
to include the centrifugal acceleration. We have studied the behaviour of the
drag index for the Kerr metric and the Neugebauer-Meinel metric representing a
self-gravitating rotating disk and their Newtonian approximations. The
similarity of the behaviour of the index for a given set of parameters both in
the full and approximated forms, suggests that the index characterises an
intrinsic property of spacetime with rotation. Analysing the index for a given
set of parameters shows possible constraints on them.
